[XMR] Monero - A secure, private, untraceable cryptocurrency

[mindrust]

We still have Monero Speculation topic for price discussions.

https://bitcointalk.org/index.php?topic=753252.new#new

Sorry about that moving my bullshit there now. 

[dEBRUYNE]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

[anubizz]

You said that the „—prune blockchain“ option needs to be includet every time the daemon is started, right!?
My problem:
To be safe i deleted the old blockchain database and started a fully new sync. The daemon was running till 66% and then he stoped and shut down. I don‘t know why..
When i start monerod  again with „--prune blockchain“ i get the error „could not start sync- to many dirty blocks“. When i do the same with „-db salve“ instead of „-prune blockchain“ it starts to sync again but also shuts down some hours later.

The last version of the daemon was slower but worked constant. What could be the problem?

You may have accidentally corrupted the blockchain. There's also a bug in v0.14.1.0 due to which pruning on a sync from scratch does not function properly. I'd suggest to perform a normal resync from scratch and thereafter utilize the pruning tool.

A very interresting update on my situation:
I deleted the whole .bitmonero folder, cleaned up and started from scratch without the prune-tool-> same issue! At 66% the sync stops for reasons i can not find.

So just to have all tried, i created a completely new node on a different device (bananapi pro) and started sync from beginning. As i checked the logs some minutes ago i see the same problem at 66% as on the other device:
"

2019-06-27 03:24:22.495   [P2P9]   INFO   global   src/cryptonote_protocol/cryptonote_protocol_handler.inl:1390   Synced 1237971/1865802 (66%, 627831 left)
2019-06-27 15:49:30.527           b6f14210   INFO   logging   contrib/epee/src/mlog.cpp:273   New log categories: *:WARNING,net:FATAL,net.http:FATAL,net.ssl:FATAL,net.p2p:FATAL,net.cn:FATAL,global:INFO,verify:FATAL,serialization:FATAL,stacktrace:INFO,logging:INFO,msgwriter:INFO
2019-06-27 15:49:30.529           b6f14210   INFO   global   src/daemon/main.cpp:281   Monero 'Boron Butterfly' (v0.14.1.0-release)
2019-06-27 15:49:30.532           b6f14210   INFO   global   contrib/epee/src/net_ssl.cpp:124   Generating SSL certificate
2019-06-27 15:49:46.772           b6f14210   ERROR   msgwriter   src/common/scoped_message_writer.h:102   Error: Couldn't connect to daemon: 192.168.0.171:18088

"
 Whats the problem

------
Edit:

I started the sync again and watched it . After about 100 blocks it stopped with comment Segmentation fault

[dEBRUYNE]

You said that the „—prune blockchain“ option needs to be includet every time the daemon is started, right!?
My problem:
To be safe i deleted the old blockchain database and started a fully new sync. The daemon was running till 66% and then he stoped and shut down. I don‘t know why..
When i start monerod  again with „--prune blockchain“ i get the error „could not start sync- to many dirty blocks“. When i do the same with „-db salve“ instead of „-prune blockchain“ it starts to sync again but also shuts down some hours later.

The last version of the daemon was slower but worked constant. What could be the problem?

You may have accidentally corrupted the blockchain. There's also a bug in v0.14.1.0 due to which pruning on a sync from scratch does not function properly. I'd suggest to perform a normal resync from scratch and thereafter utilize the pruning tool.

A very interresting update on my situation:
I deleted the whole .bitmonero folder, cleaned up and started from scratch without the prune-tool-> same issue! At 66% the sync stops for reasons i can not find.

So just to have all tried, i created a completely new node on a different device (bananapi pro) and started sync from beginning. As i checked the logs some minutes ago i see the same problem at 66% as on the other device:
"

2019-06-27 03:24:22.495   [P2P9]   INFO   global   src/cryptonote_protocol/cryptonote_protocol_handler.inl:1390   Synced 1237971/1865802 (66%, 627831 left)
2019-06-27 15:49:30.527           b6f14210   INFO   logging   contrib/epee/src/mlog.cpp:273   New log categories: *:WARNING,net:FATAL,net.http:FATAL,net.ssl:FATAL,net.p2p:FATAL,net.cn:FATAL,global:INFO,verify:FATAL,serialization:FATAL,stacktrace:INFO,logging:INFO,msgwriter:INFO
2019-06-27 15:49:30.529           b6f14210   INFO   global   src/daemon/main.cpp:281   Monero 'Boron Butterfly' (v0.14.1.0-release)
2019-06-27 15:49:30.532           b6f14210   INFO   global   contrib/epee/src/net_ssl.cpp:124   Generating SSL certificate
2019-06-27 15:49:46.772           b6f14210   ERROR   msgwriter   src/common/scoped_message_writer.h:102   Error: Couldn't connect to daemon: 192.168.0.171:18088

"
 Whats the problem

------
Edit:

I started the sync again and watched it . After about 100 blocks it stopped with comment Segmentation fault

Do you have sufficient free disk space on both systems? Also, why are you using a non default port?

[Mek]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

Yes and Monero folder is under exclusions. And disabling AV makes no difference. Previous version (v12) worked without problems.

[anubizz]

You said that the „—prune blockchain“ option needs to be includet every time the daemon is started, right!?
My problem:
To be safe i deleted the old blockchain database and started a fully new sync. The daemon was running till 66% and then he stoped and shut down. I don‘t know why..
When i start monerod  again with „--prune blockchain“ i get the error „could not start sync- to many dirty blocks“. When i do the same with „-db salve“ instead of „-prune blockchain“ it starts to sync again but also shuts down some hours later.

The last version of the daemon was slower but worked constant. What could be the problem?

You may have accidentally corrupted the blockchain. There's also a bug in v0.14.1.0 due to which pruning on a sync from scratch does not function properly. I'd suggest to perform a normal resync from scratch and thereafter utilize the pruning tool.

A very interresting update on my situation:
I deleted the whole .bitmonero folder, cleaned up and started from scratch without the prune-tool-> same issue! At 66% the sync stops for reasons i can not find.

So just to have all tried, i created a completely new node on a different device (bananapi pro) and started sync from beginning. As i checked the logs some minutes ago i see the same problem at 66% as on the other device:
"

2019-06-27 03:24:22.495   [P2P9]   INFO   global   src/cryptonote_protocol/cryptonote_protocol_handler.inl:1390   Synced 1237971/1865802 (66%, 627831 left)
2019-06-27 15:49:30.527           b6f14210   INFO   logging   contrib/epee/src/mlog.cpp:273   New log categories: *:WARNING,net:FATAL,net.http:FATAL,net.ssl:FATAL,net.p2p:FATAL,net.cn:FATAL,global:INFO,verify:FATAL,serialization:FATAL,stacktrace:INFO,logging:INFO,msgwriter:INFO
2019-06-27 15:49:30.529           b6f14210   INFO   global   src/daemon/main.cpp:281   Monero 'Boron Butterfly' (v0.14.1.0-release)
2019-06-27 15:49:30.532           b6f14210   INFO   global   contrib/epee/src/net_ssl.cpp:124   Generating SSL certificate
2019-06-27 15:49:46.772           b6f14210   ERROR   msgwriter   src/common/scoped_message_writer.h:102   Error: Couldn't connect to daemon: 192.168.0.171:18088

"
 Whats the problem

------
Edit:

I started the sync again and watched it . After about 100 blocks it stopped with comment Segmentation fault

Do you have sufficient free disk space on both systems? Also, why are you using a non default port?

Used: 15.48GB (14.13%) Free: 94.06GB Total: 109.53GB
So space is not the problem.

I choosed a random port. Is that important? I changed to 18081 now.

[dEBRUYNE]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

Yes and Monero folder is under exclusions. And disabling AV makes no difference. Previous version (v12) worked without problems.

Can you try launching via the start-low-graphics-mode.bat batch file that is included?

[dEBRUYNE]

You said that the „—prune blockchain“ option needs to be includet every time the daemon is started, right!?
My problem:
To be safe i deleted the old blockchain database and started a fully new sync. The daemon was running till 66% and then he stoped and shut down. I don‘t know why..
When i start monerod  again with „--prune blockchain“ i get the error „could not start sync- to many dirty blocks“. When i do the same with „-db salve“ instead of „-prune blockchain“ it starts to sync again but also shuts down some hours later.

The last version of the daemon was slower but worked constant. What could be the problem?

You may have accidentally corrupted the blockchain. There's also a bug in v0.14.1.0 due to which pruning on a sync from scratch does not function properly. I'd suggest to perform a normal resync from scratch and thereafter utilize the pruning tool.

A very interresting update on my situation:
I deleted the whole .bitmonero folder, cleaned up and started from scratch without the prune-tool-> same issue! At 66% the sync stops for reasons i can not find.

So just to have all tried, i created a completely new node on a different device (bananapi pro) and started sync from beginning. As i checked the logs some minutes ago i see the same problem at 66% as on the other device:
"

2019-06-27 03:24:22.495   [P2P9]   INFO   global   src/cryptonote_protocol/cryptonote_protocol_handler.inl:1390   Synced 1237971/1865802 (66%, 627831 left)
2019-06-27 15:49:30.527           b6f14210   INFO   logging   contrib/epee/src/mlog.cpp:273   New log categories: *:WARNING,net:FATAL,net.http:FATAL,net.ssl:FATAL,net.p2p:FATAL,net.cn:FATAL,global:INFO,verify:FATAL,serialization:FATAL,stacktrace:INFO,logging:INFO,msgwriter:INFO
2019-06-27 15:49:30.529           b6f14210   INFO   global   src/daemon/main.cpp:281   Monero 'Boron Butterfly' (v0.14.1.0-release)
2019-06-27 15:49:30.532           b6f14210   INFO   global   contrib/epee/src/net_ssl.cpp:124   Generating SSL certificate
2019-06-27 15:49:46.772           b6f14210   ERROR   msgwriter   src/common/scoped_message_writer.h:102   Error: Couldn't connect to daemon: 192.168.0.171:18088

"
 Whats the problem

------
Edit:

I started the sync again and watched it . After about 100 blocks it stopped with comment Segmentation fault

Do you have sufficient free disk space on both systems? Also, why are you using a non default port?

Used: 15.48GB (14.13%) Free: 94.06GB Total: 109.53GB
So space is not the problem.

I choosed a random port. Is that important? I changed to 18081 now.

Could you perhaps, for testing purposes, try a full resync from scratch with the default port?

[anubizz]

You said that the „—prune blockchain“ option needs to be includet every time the daemon is started, right!?
My problem:
To be safe i deleted the old blockchain database and started a fully new sync. The daemon was running till 66% and then he stoped and shut down. I don‘t know why..
When i start monerod  again with „--prune blockchain“ i get the error „could not start sync- to many dirty blocks“. When i do the same with „-db salve“ instead of „-prune blockchain“ it starts to sync again but also shuts down some hours later.

The last version of the daemon was slower but worked constant. What could be the problem?

You may have accidentally corrupted the blockchain. There's also a bug in v0.14.1.0 due to which pruning on a sync from scratch does not function properly. I'd suggest to perform a normal resync from scratch and thereafter utilize the pruning tool.

A very interresting update on my situation:
I deleted the whole .bitmonero folder, cleaned up and started from scratch without the prune-tool-> same issue! At 66% the sync stops for reasons i can not find.

So just to have all tried, i created a completely new node on a different device (bananapi pro) and started sync from beginning. As i checked the logs some minutes ago i see the same problem at 66% as on the other device:
"

2019-06-27 03:24:22.495   [P2P9]   INFO   global   src/cryptonote_protocol/cryptonote_protocol_handler.inl:1390   Synced 1237971/1865802 (66%, 627831 left)
2019-06-27 15:49:30.527           b6f14210   INFO   logging   contrib/epee/src/mlog.cpp:273   New log categories: *:WARNING,net:FATAL,net.http:FATAL,net.ssl:FATAL,net.p2p:FATAL,net.cn:FATAL,global:INFO,verify:FATAL,serialization:FATAL,stacktrace:INFO,logging:INFO,msgwriter:INFO
2019-06-27 15:49:30.529           b6f14210   INFO   global   src/daemon/main.cpp:281   Monero 'Boron Butterfly' (v0.14.1.0-release)
2019-06-27 15:49:30.532           b6f14210   INFO   global   contrib/epee/src/net_ssl.cpp:124   Generating SSL certificate
2019-06-27 15:49:46.772           b6f14210   ERROR   msgwriter   src/common/scoped_message_writer.h:102   Error: Couldn't connect to daemon: 192.168.0.171:18088

"
 Whats the problem

------
Edit:

I started the sync again and watched it . After about 100 blocks it stopped with comment Segmentation fault

Do you have sufficient free disk space on both systems? Also, why are you using a non default port?

Used: 15.48GB (14.13%) Free: 94.06GB Total: 109.53GB
So space is not the problem.

I choosed a random port. Is that important? I changed to 18081 now.

Could you perhaps, for testing purposes, try a full resync from scratch with the default port?

My plan was to to delete EVERYTHING on my cubietruck! Flat all content and then start with a fresh OS and daemon.
What makes me confused the most is that i had it synced to 100% already... then i wanted to be save in every way and deleted the blockchain folder to start new, and now a lot of problems come up..

But to answer your question: Yes, i can do so!
p2p on port 18080 (opened firewall port) bound to ip 0.0.0.0
rpc on port 18081 (port closed on fw) bound to internal ip 192.168.xxx

I will let you know soon.

[anubizz]

Same problem, but this time the error happened at 9% sync. 
Seems to be a SSL problem...

[Mek]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

Yes and Monero folder is under exclusions. And disabling AV makes no difference. Previous version (v12) worked without problems.

Can you try launching via the start-low-graphics-mode.bat batch file that is included?

That was one of the first things I tried but forgot to mention... same result: the gui exe only appears in task manager and then immediately quits, with no log created.

[dEBRUYNE]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

Yes and Monero folder is under exclusions. And disabling AV makes no difference. Previous version (v12) worked without problems.

Can you try launching via the start-low-graphics-mode.bat batch file that is included?

That was one of the first things I tried but forgot to mention... same result: the gui exe only appears in task manager and then immediately quits, with no log created.

I have a feeling your AV is still deleting necessary files (i.e. files required in order for the GUI to run properly). Can you perhaps try these steps:

1. Reboot to ensure all Monero related processes are closed.

2. Apply this guide -> https://monero.stackexchange.com/questions/10798/my-antivirus-av-software-blocks-quarantines-the-monero-gui-wallet-is-there

3. Note that step 2. implies that you have to re-extract the .zip file.

4. Start monero-wallet-gui.exe again. Does it launch properly now?

[dEBRUYNE]

Same problem, but this time the error happened at 9% sync. 
Seems to be a SSL problem...

Could you perhaps open a new issue on the Monero Github repository?

https://github.com/monero-project/monero/issues/new

[Kryptowerk]

Last few of the first ever funded Monero giftcards available here: https://bitcointalk.org/index.php?topic=5140464.0

I was just thinking about giving cryptocurrencies as a gift for special occasions, it can be a very good gift. Similar to small gold bars. I already gave a paper wallet as a gift to one of my family members, but you've taken it to next level, very nice design. Happy to see there is interest for them.

Ha, yes, that's the idea: An eye-catcher for those maybe still totally unfamiliar with Monero. So far the reviews on the cards have been great. 

[anubizz]

Same problem, but this time the error happened at 9% sync. 
Seems to be a SSL problem...

Could you perhaps open a new issue on the Monero Github repository?

https://github.com/monero-project/monero/issues/new

I will have to create an account first. But u will do so when i have the time to.

[dEBRUYNE]

Same problem, but this time the error happened at 9% sync. 
Seems to be a SSL problem...

Could you perhaps open a new issue on the Monero Github repository?

https://github.com/monero-project/monero/issues/new

I will have to create an account first. But u will do so when i have the time to.

Thanks.

[Mek]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

Yes and Monero folder is under exclusions. And disabling AV makes no difference. Previous version (v12) worked without problems.

Can you try launching via the start-low-graphics-mode.bat batch file that is included?

That was one of the first things I tried but forgot to mention... same result: the gui exe only appears in task manager and then immediately quits, with no log created.

I have a feeling your AV is still deleting necessary files (i.e. files required in order for the GUI to run properly). Can you perhaps try these steps:

1. Reboot to ensure all Monero related processes are closed.

2. Apply this guide -> https://monero.stackexchange.com/questions/10798/my-antivirus-av-software-blocks-quarantines-the-monero-gui-wallet-is-there

3. Note that step 2. implies that you have to re-extract the .zip file.

4. Start monero-wallet-gui.exe again. Does it launch properly now?

That made me try one more thing: back up all Monero folder contents into a 7z file, delete all files and folders from inside Monero folder, and extract downloaded Monero wallet files anew (so that there are no leftovers from older versions). Monero GUI wallet is now running as it should. But I don't know why, it launches the daemon (monerod.exe) in a separate command line window. Previously it ran only in the background, not displaying a separate window. Probably that has been changed, but is no big issue, just noticing.

[dzonikg28]

Last few of the first ever funded Monero giftcards available here: https://bitcointalk.org/index.php?topic=5140464.0

I was just thinking about giving cryptocurrencies as a gift for special occasions, it can be a very good gift. Similar to small gold bars. I already gave a paper wallet as a gift to one of my family members, but you've taken it to next level, very nice design. Happy to see there is interest for them.

Ha, yes, that's the idea: An eye-catcher for those maybe still totally unfamiliar with Monero. So far the reviews on the cards have been great. 

Those gift cards look neat! No idea though if that will attract any Monero newcomers. I think it is mostly those who are already familiar with Monero who also might choose to use those cards.

[dEBRUYNE]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

Yes and Monero folder is under exclusions. And disabling AV makes no difference. Previous version (v12) worked without problems.

Can you try launching via the start-low-graphics-mode.bat batch file that is included?

That was one of the first things I tried but forgot to mention... same result: the gui exe only appears in task manager and then immediately quits, with no log created.

I have a feeling your AV is still deleting necessary files (i.e. files required in order for the GUI to run properly). Can you perhaps try these steps:

1. Reboot to ensure all Monero related processes are closed.

2. Apply this guide -> https://monero.stackexchange.com/questions/10798/my-antivirus-av-software-blocks-quarantines-the-monero-gui-wallet-is-there

3. Note that step 2. implies that you have to re-extract the .zip file.

4. Start monero-wallet-gui.exe again. Does it launch properly now?

That made me try one more thing: back up all Monero folder contents into a 7z file, delete all files and folders from inside Monero folder, and extract downloaded Monero wallet files anew (so that there are no leftovers from older versions). Monero GUI wallet is now running as it should. But I don't know why, it launches the daemon (monerod.exe) in a separate command line window. Previously it ran only in the background, not displaying a separate window. Probably that has been changed, but is no big issue, just noticing.

That is due to a bug in the build system and the issue is kind of difficult to debug. However, I expect it to be fixed once deterministic builds are available for the GUI (we're working with TheCharlatan to get deterministic builds going for the GUI).

[anubizz]

Hi,
I upgraded my wallet from v12 to v14. But I am having an issue: monero-wallet-gui.exe does not work. It only appears in Task Manager for a second, and then immediately exits. No log file is created so I am at a loss what happens. Previous version worked OK.
I downloaded the archive from official website (not the installer) and replaced all files in my Monero folder as usual. Since then, monero-wallet-gui.exe did not work.
I then ran monerod.exe, which worked OK. At first it upgraded blockchain database from version 1 to version 2, then 3, then 4 (if I remember correctly). It is synchronizing blocks as I write this post. So my blockchain db is not corrupt. I tried running the GUI wallet while monerod.exe is running, same result. And turned off Avast antivirus temporarily, same result.
Can anyone advise what to do, please?

Do you have active AV (AntiVirus) software on that system?

Yes and Monero folder is under exclusions. And disabling AV makes no difference. Previous version (v12) worked without problems.

Can you try launching via the start-low-graphics-mode.bat batch file that is included?

That was one of the first things I tried but forgot to mention... same result: the gui exe only appears in task manager and then immediately quits, with no log created.

I have a feeling your AV is still deleting necessary files (i.e. files required in order for the GUI to run properly). Can you perhaps try these steps:

1. Reboot to ensure all Monero related processes are closed.

2. Apply this guide -> https://monero.stackexchange.com/questions/10798/my-antivirus-av-software-blocks-quarantines-the-monero-gui-wallet-is-there

3. Note that step 2. implies that you have to re-extract the .zip file.

4. Start monero-wallet-gui.exe again. Does it launch properly now?

That made me try one more thing: back up all Monero folder contents into a 7z file, delete all files and folders from inside Monero folder, and extract downloaded Monero wallet files anew (so that there are no leftovers from older versions). Monero GUI wallet is now running as it should. But I don't know why, it launches the daemon (monerod.exe) in a separate command line window. Previously it ran only in the background, not displaying a separate window. Probably that has been changed, but is no big issue, just noticing.

That is due to a bug in the build system and the issue is kind of difficult to debug. However, I expect it to be fixed once deterministic builds are available for the GUI (we're working with TheCharlatan to get deterministic builds going for the GUI).

After reading Meks posts i checked my monerod log files and it seems his problem and mine are similar in some things. I made a fresh setup (again) and built everything up from zero. So there is no old data left.
Same result at 65%- some SSL error
After starting monerod again, again and again i checked the monerod logs again: The log file from monerod stops updating after the first run and the following error!
Similar to what Mek said...

Btw. I am running monerod on a seperate linux mashine only used for monero. Nothing else then ubuntu and monero installed.