Could not load wallet file: the error message was null

[HCP]

Oohhhhhhhh OK... so YAY! #greatSuccess

[Lucius]

I am still using old Multibit Classic 0.5.19 and yesterday when I was open wallet there is some message that could not load wallet/or something like that,it just start to sync and after some time after sync everything is working.Today I open wallet again and same thing happened,so it is time to import private keys in other wallet.I read that maybe some of files(spv chain file) is corrupted so wallet is sync every time when is open,someone who had a similar experience?

[HCP]

Are you getting an error message relating to a "BlockStoreException"?? If so, you could try the following:

1. Shut down MB Classic.
2. Backup the files in your "%appdata%/MultiBit" directory.
NOTE: For windows 7-10, this is usually something like c:\Users\YOURPCUSERNAME\AppData\Roaming\MultiBit
Examples for OSX/Linux here: https://multibit.org/help/v0.5/help_troubleshooting.html

3. Delete the multibit.spvchain from your "%appdata%/MultiBit" directory.
4. Open MB Classic and let it sync.

If that still doesn't help, can you look in "View -> Messages" and see if there are any error messages posted there... if there isn't anything obvious there, have a look in the multibit.log file that should be in "%appdata%/MultiBit/log" directory.


Also, you should really upgrade to a better wallet. MBC 0.5.19 is no longer maintained or supported by the devs... the max fee it will use allow you to use is 0.0005 btc which will be a max of ~220 sats/byte) and you may find your transactions always take a long time to confirm (especially with the current 300+ sats/byte fee levels!)

[Lucius]

Are you getting an error message relating to a "BlockStoreException"?? If so, you could try the following:

1. Shut down MB Classic.
2. Backup the files in your "%appdata%/MultiBit" directory.
NOTE: For windows 7-10, this is usually something like c:\Users\YOURPCUSERNAME\AppData\Roaming\MultiBit
Examples for OSX/Linux here: https://multibit.org/help/v0.5/help_troubleshooting.html

3. Delete the multibit.spvchain from your "%appdata%/MultiBit" directory.
4. Open MB Classic and let it sync.

If that still doesn't help, can you look in "View -> Messages" and see if there are any error messages posted there... if there isn't anything obvious there, have a look in the multibit.log file that should be in "%appdata%/MultiBit/log" directory.


Also, you should really upgrade to a better wallet. MBC 0.5.19 is no longer maintained or supported by the devs... the max fee it will use allow you to use is 0.0005 btc which will be a max of ~220 sats/byte) and you may find your transactions always take a long time to confirm (especially with the current 300+ sats/byte fee levels!)

I just checked and message is that The wallet "C:\Users\Home\AppData\Roaming\MultiBit\multibit.wallet" could not be loaded. Loading the backup wallet.I have two wallet in MB and this is always working without problem,now for some reason my main wallet is not loading after open MB.

I have backup of all files and private keys so I delete spvchain file and open wallet,same message is show again and I choose option to reset blockchain and transaction,now waiting to wallet sync.

Regarding upgrading to new wallet,I am already import my private keys to Electrum,thanks for help and advice

[NeuroticFish]

I am still using old Multibit Classic 0.5.19 and yesterday when I was open wallet there is some message that could not load wallet/or something like that,it just start to sync and after some time after sync everything is working.Today I open wallet again and same thing happened,so it is time to import private keys in other wallet.I read that maybe some of files(spv chain file) is corrupted so wallet is sync every time when is open,someone who had a similar experience?

I had this problem in the past. After 2-3 such silly restarts, it stabilized and had the data OK. But my guess is that I was just lucky.
However, I did the same as you back then: I switched to Electrum and I am happy with that choice.

A word of advice though: keep your private key (if you use the same wallet) or the seed words (if you made a new wallet) somewhere safe. Even Electrum is not perfect - some cry from time to time that they cannot start Electrum and it's better to have your back covered.

[HCP]

I just checked and message is that The wallet "C:\Users\Home\AppData\Roaming\MultiBit\multibit.wallet" could not be loaded. Loading the backup wallet.I have two wallet in MB and this is always working without problem,now for some reason my main wallet is not loading after open MB.

Ahhhh ok. I suspect that this might be similar to the MultiBitHD issue with "Password did not unlock the wallet". There may be a transaction that is failing a "hash" calculation because the bitcoinj library is out of date. Which makes the app think your wallet is corrupt when it isn't.

I think I've seen another case of this, but can't find the thread.

If it still errors out after you have finished syncing, can you check the debug log in %appdata%/MultiBit/log directory and see if you get anything more specific error-wise.

[Lucius]

I am still using old Multibit Classic 0.5.19 and yesterday when I was open wallet there is some message that could not load wallet/or something like that,it just start to sync and after some time after sync everything is working.Today I open wallet again and same thing happened,so it is time to import private keys in other wallet.I read that maybe some of files(spv chain file) is corrupted so wallet is sync every time when is open,someone who had a similar experience?

I had this problem in the past. After 2-3 such silly restarts, it stabilized and had the data OK. But my guess is that I was just lucky.
However, I did the same as you back then: I switched to Electrum and I am happy with that choice.

A word of advice though: keep your private key (if you use the same wallet) or the seed words (if you made a new wallet) somewhere safe. Even Electrum is not perfect - some cry from time to time that they cannot start Electrum and it's better to have your back covered.

No luck for me with MultiBit Classic this time,so Electrum is now my new wallet-have some small problems so far but my coins are safe,I export private keys long time ago

I just checked and message is that The wallet "C:\Users\Home\AppData\Roaming\MultiBit\multibit.wallet" could not be loaded. Loading the backup wallet.I have two wallet in MB and this is always working without problem,now for some reason my main wallet is not loading after open MB.

Ahhhh ok. I suspect that this might be similar to the MultiBitHD issue with "Password did not unlock the wallet". There may be a transaction that is failing a "hash" calculation because the bitcoinj library is out of date. Which makes the app think your wallet is corrupt when it isn't.

I think I've seen another case of this, but can't find the thread.

If it still errors out after you have finished syncing, can you check the debug log in %appdata%/MultiBit/log directory and see if you get anything more specific error-wise.

I delete spv file and wallet is start to sync and on some 20% it stop and start again from 0.For full sync it take 2+ hour but after closing and starting wallet again it just start to sync again.I check log data and there are some errors recorded:

Loading wallet from 'C:\Users\Home\AppData\Roaming\MultiBit\multibit.wallet'
com.google.bitcoin.store.UnreadableWalletException: Transaction did not deserialize completely

ERROR c.g.bitcoin.net.ConnectionHandler - Error writing message to connection, closing connection java.nio.channels.CancelledKeyException

It seems that there is some serious problem,some time ago I have also similar problem with Multi Doge wallet and even after clean install and many attempts I did not manage to run that wallet again.

[HCP]

I delete spv file and wallet is start to sync and on some 20% it stop and start again from 0.For full sync it take 2+ hour but after closing and starting wallet again it just start to sync again.I check log data and there are some errors recorded:

Loading wallet from 'C:\Users\Home\AppData\Roaming\MultiBit\multibit.wallet'
com.google.bitcoin.store.UnreadableWalletException: Transaction did not deserialize completely

This looks pretty much exactly like the error plaguing MultiBit HD at the moment... Something got changed with the way transaction hashes are calculated back in Feb... I believe a "Version" field got added in to the mix... https://github.com/bitcoinj/bitcoinj/commit/be09b620626681c9e51a211ee314a34cb7958a12

Newer versions of bitcoinj obviously work... as they have this new modification, but MultiBit Classic and MultiBit HD both use an older bitcoinj library... so they don't have the version field and therefore generate a hash that is different... the hash comparison fails... and the very obscure error message comes out that "the wallet could not be loaded."

At this point, I don't think there is anything you can do to make MBC start working properly again   Unless you feel like recompiling with an up-to-date bitcoinj library included. There is pretty much zero chance of this bug ever being fixed in MBC by the Devs as MBC is no longer developed or maintained from what I can tell... and it isn't looking all that great for MBHD either! I reported the issue to them like a month ago... and no sign of an update as yet

I suggest you let it sync up fully... DON'T close the wallet... then export your keys (Tools-> "Export Private Keys")... DON'T put a password on the file:


Then you can open the .key file in a text editor and get all your keys and import/sweep them into another wallet... Personally, I recommend Electrum as a solid replacement for MBC and MBHD users.

[Lucius]

I delete spv file and wallet is start to sync and on some 20% it stop and start again from 0.For full sync it take 2+ hour but after closing and starting wallet again it just start to sync again.I check log data and there are some errors recorded:

Loading wallet from 'C:\Users\Home\AppData\Roaming\MultiBit\multibit.wallet'
com.google.bitcoin.store.UnreadableWalletException: Transaction did not deserialize completely

This looks pretty much exactly like the error plaguing MultiBit HD at the moment... Something got changed with the way transaction hashes are calculated back in Feb... I believe a "Version" field got added in to the mix... https://github.com/bitcoinj/bitcoinj/commit/be09b620626681c9e51a211ee314a34cb7958a12

Newer versions of bitcoinj obviously work... as they have this new modification, but MultiBit Classic and MultiBit HD both use an older bitcoinj library... so they don't have the version field and therefore generate a hash that is different... the hash comparison fails... and the very obscure error message comes out that "the wallet could not be loaded."

At this point, I don't think there is anything you can do to make MBC start working properly again   Unless you feel like recompiling with an up-to-date bitcoinj library included. There is pretty much zero chance of this bug ever being fixed in MBC by the Devs as MBC is no longer developed or maintained from what I can tell... and it isn't looking all that great for MBHD either! I reported the issue to them like a month ago... and no sign of an update as yet

I suggest you let it sync up fully... DON'T close the wallet... then export your keys (Tools-> "Export Private Keys")... DON'T put a password on the file:


Then you can open the .key file in a text editor and get all your keys and import/sweep them into another wallet... Personally, I recommend Electrum as a solid replacement for MBC and MBHD users.

Only thing I will try is to install new copy of MB and then import my private keys,just to check is wallet.dat file causes this problem,but if your explanation is correct then MultiBit is no longer for use-some say it has been so for long time.

I wrote already that now I use Electrum,have my private keys export long time ago from MB.Thanks for help&advice again

[HCP]

Only thing I will try is to install new copy of MB and then import my private keys,just to check is wallet.dat file causes this problem,but if your explanation is correct then MultiBit is no longer for use-some say it has been so for long time.

Yep... MBC is basically "abandoned"... they claim it is in "maintenance mode", but given they haven't even fixed their "current" version (MBHD), I very much doubt that MBC will be updated ever.

MultiBit Classic
MultiBit Classic is:

free and open source under the MIT licence
designed to work directly with any Bitcoin full node (no servers)
not related to the Bitcoin Classic full node project
a legacy product so you should upgrade to MultiBit HD
It is now considered to be a legacy product and is in maintenance mode. This means that only essential security and network compatibility updates will be made to the codebase.

The security model of MultiBit Classic is weaker than MultiBit HD so we only recommend using it if you have private keys that cannot be migrated.

Note that release numbers are not continuous but are based on distributions made available through the main website

[Lucius]

Only thing I will try is to install new copy of MB and then import my private keys,just to check is wallet.dat file causes this problem,but if your explanation is correct then MultiBit is no longer for use-some say it has been so for long time.

Yep... MBC is basically "abandoned"... they claim it is in "maintenance mode", but given they haven't even fixed their "current" version (MBHD), I very much doubt that MBC will be updated ever.

MultiBit Classic
MultiBit Classic is:

free and open source under the MIT licence
designed to work directly with any Bitcoin full node (no servers)
not related to the Bitcoin Classic full node project
a legacy product so you should upgrade to MultiBit HD
It is now considered to be a legacy product and is in maintenance mode. This means that only essential security and network compatibility updates will be made to the codebase.

The security model of MultiBit Classic is weaker than MultiBit HD so we only recommend using it if you have private keys that cannot be migrated.

Note that release numbers are not continuous but are based on distributions made available through the main website

I remove my wallet and all files and install fresh copy of MultiBit Classic-import my private keys and wallet is sync and working normal,I even send one transaction.But when I close wallet and open again there is no balance/wallet,just empty MB with big 0.Nothing else can not be done regarding this problem,so advice to anyone to just send your coins to some other wallet.

[radowch]

Hi All

Im having this same problem and trying to download other versions of multibit and the same error is being returned.
i reverted back to all versions below 5.18 with zero success.

ive made backup of my wallet already as well just incase.
is there anything else i can try doing?

appreciate the help.

Can you remember if you put a password on your wallet? If you didn't try opening your wallet file in notepad and looking for "org.bitcoi[Suspicious link removed]oduction" at the start of it. Newer wallets are in a format called protobuf, and newer wallets without a password definitely start with "org.bitcoi[Suspicious link removed]oduction". I'm not sure what older format wallets start with.

If you have a newer format of wallet without a password the instructions in the quote below might work. Any hex editor should work as well as the one I linked to in the quote,

If you have an older format wallet (called serialised format) you can try adapting the instructions in the quote. I can't test them because I can't find a download for an old enough version of multibit. You search for "75 71 00 7e 00 11 00 00 00 41". If you find that series of bytes you probably have an older format wallet. In that case you can either try using the instructions at this link.

https://bitcointalk.org/index.php?topic=43616.msg909038#msg909038

Alternatively you can search for each 20 in the file and copy the 32 bytes following every instance of 20. They might be private keys. If you remove any spaces and put them into the offline webpage described in the quote it will reject any false positives, and show any real private keys in a range of formats you can import into electrum.

Since version 0.4.0 multibit classic wallet files are in a format called Google protocol buffer format (protobuf). Open a file with a .wallet extension in a hex editor and look for the following sequence of bytes 08 01 12 20. The next 32 bytes after that should be your private key in hex format. After you get your private key in hex format you can convert it to a normal format using an offline copy of the bitaddress website.

I tested this on an unencrypted wallet (one with no password) in multibit version 0.5.1.6 and it worked for me.

This is the hex editor I used, although any other is probably sufficient.

http[Suspicious link removed]ditor.org/home.php

This is the bitaddress website. I advise you not to directly paste private keys into it.

https://www.bitaddress.org/

Instead look for this link at the bottom of the page and use it to download a zipped copy you can run offline.

https://github.com/pointbiz/bitaddress.org/archive/v3.3.0.zip



This is my multibit wallet file opened in the hex editor with the bytes 08 01 12 20 that precede a private key highlighted.


https://i.imgur.com/AjyUKQG.png



This is the 32 bytes of a private key (in hex format) highlighted.



https://i.imgur.com/dpTWlkS.png



This is the 32 bytes of a private key (in hex format) copied directly from the hex editor into notepad.


https://i.imgur.com/q3Gx5JW.png



This is the 32 bytes of a private key after removing the spaces in notepad.


https://i.imgur.com/zAHJn0q.png



This is the private key copied from notepad and pasted into an offline copy of the bitaddress wedsite. Click the view details button to get the private key converted to normal formats.


https://i.imgur.com/ocV54EW.png


This is my multibit wallet's address 1F84fkbMng6dJpGZmtycRbUe72B7XSYbeT shown on the right hand side of bitaddress. Every raw private key can convert into two different bitcoin addresses, which is why there's two.


https://i.imgur.com/NtL8U7X.png



This is my multibit wallet's address 1F84fkbMng6dJpGZmtycRbUe72B7XSYbeT shown in multibit.

https://i.imgur.com/CAeWY5t.png


You can import your private key into the wallet of your choice to get control of yours coins back. Electrum's a good choice.

If you install electrum you can use these instructions to import your private keys from multibit into it.

http://docs.electrum.org/en/latest/faq.html#can-i-import-private-keys-from-other-bitcoin-clients

Hey man,

my name is Jorge and I am from Madrid. I don't know you and you don't know me but you just became my friend. You just helped me recover some money with your replies at as i was having serious issues recovering my old multibit wallet. I finally got to extract a private key and recover my btc.

So I just wanted to thank you and encorage you to keep helping others, you are so fucking good at it and we, the ignorant people of the internet, need guys like you so badly.

Cheers mate!

[wooly7]

HI all,

I am also having and issue accessing my Multibit classic Wallet, it says the null message.

I have tried using python to run the scripts but keep getting this

IOError: [Errno 2] No such file or directory: Freshy.Wallet

running directory C:\Python27\Scripts\multibit_recovery-master\decrypt_multibit_classic_walletkeys.py Freshy.wallet.

The .Wallet file is in that directory and it doesnt load the scrips

IF anyone has an idea please let me know.

Thanks all.
Wooly

[HCP]

If you're using Windows 10, it could quite possibly be a "permission" error... I was attempting something the other night and some Python scripts were kicking out errors because some of the new Windows 10 defender and security settings attempt to block reading/writing from some C:\ folders

Try starting the command prompt as administrator:

1. Click the "Start" button (press Windows key)
2. Type: command prompt - you should see something like this: 

3. Click the "Run as administrator" option on the right hand side

You should see the command prompt open with admin privileges:


Note how it says "Administrator: command prompt" in the title bar... give that a go and see if the Python script works ok then.