Multibit Client blank! Emptied what happened?

[shkiser]

Opened wallet today and it is blank! No bitcoins showing, where I had about 30.. Also No transactions history is showing, no nothing showing! What the fuck is going on? When I plugged in my usb drive that Ive saved my wallet to it all synced up and is showing all info now. How come when I opened client it wasnt pointing to my wallet? Ive never seen this happen before, usually it loads my wallet right away. Should I be worried about this? Also since I have my wallet. file saved to my usb is it safe to delete the wallet file the hardrive of my computer? Or should I just save it to truecrypt or something along with also keep it saved to usb?

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[shkiser]

When I removed my USB drive, the client went blank again, and said updates have stopped because another program has made changes to multibit client.. This was immediately apon removing my usb device.. Is there something going on with the client, that is causing these issues? The wallet.dat file is still on my hard drive, so why is the client not picking it up? Can anyone please give me some insight into this? I have a feeling something is off. Are there updates pending that are causing this issue ? Any info would be appreciate greatly.

[jim618]

I think the root cause of the problem is how/'when you are inserting your USB drive. Also I think you have the wallet in the USB drive open in MultiBit rather than the one in your user data area.

MultiBit writes to the wallet fairly often (when you changes things, when a block appears, when you do a send etc. There is a background thread that writes every couple of minutes if the wallet has been updated.)

If you have a wallet open that is on your USB drive you should only remove your USB drive when MultiBit has been shut down or you have closed the wallet.  Otherwise it will try writing to the wallet, see that it is missing (the drive has disappeared) and then complain that something else has changed the wallet and not let you do much with it. It cannot write any updates to the wallet when it needs to.

I think if you get into the habit of:
1) shutting down MultiBit or closing any wallet on the USB drive (using File | Close Wallet)
2) ejecting the USB drive in your operating system
3) physically removing it

you shouldn't see these problems.

If you look in the title bar of the main MultiBit screen you can see the path of the active wallet so you can see exactly which wallet file you have open.

[shkiser]

When I go into appdata to select my wallet file and ultimately make the client read my wallet, there are like 5 different .wallet files. I dont recall all of these being there, how do I tell which is my actual wallet?

[jim618]

The default wallet name is 'multibit.wallet'. This is the one you want. The ones with numbers in (actually timestamps) are backups that you can ignore. You probably have more backups that usual because of what happened before. If it has problems writing to the 'real' wallet it makes a backup just in case. Normally this is overkill but it can be very useful sometimes.

[freemoney458]

Hi Jim,

it sounds like this a possible way to loose bitcoins:

1) user opens/creates a new a wallet on USB pendrive
2) user removes USB pendrive with the MutliBit client still open while some background task is still writing to the USB pendrive
3) MutliBit notices that something went wrong during storage but does not find a storage medium.

Would it be a solution that MultiBit asks the user (e.g. in a dialog box) to provide a new storage place and filename in case of 3)?

[jim618]

Hi Freemoney,

I think it is unlikely because of the checks being made.
The only way to permanently lose bitcoin is to lose your private keys.

If you create a new wallet it will either succeed (new key written to disk ok) or fail (user gets error message).

When you are creating new private keys MultiBit checks that the wallet has not been changed before it adds them - it keeps a running check on date and size of the wallet.  If it sees the wallet has disappeared it won't write any additional private keys. If you managed to wait until the check was done and then the millisecond later managed to remove the USB drive then you would get an error message that the wallet was not written.

There is already an issue raised to give more protection to if people simply remove a USB drive :
https://github.com/jim618/multibit/issues/40

It gets a bit clumsy if you save it somewhere else as now you have 'old wallet on USB drive' and 'new wallet saved somewhere else'.

The checks on date and age are also there to protect against multiple processes/ MultiBits writing to the same wallet (say if it was on a network drive). I don't really want MultiBit to 'work' very well in these situations as it encourages people to do it and you are really in an edge situation at this point. It is safer to say "Something has happened to the wallet but I don't know what (out of my scope). I won't write to it any more". Sometimes it is better to fail and stop rather than push further into the unknown.

edit: a further complication is that dirty wallets are written when MultiBit shuts down and the user interface may have gone. This makes it unreliable to solicit information from the user - the computer may be shutting down and so you just want to write out the wallets straight away.

[shkiser]

im not exactly sure what happened. It seems that for whatever reason the client when I opened it wasnt directed to my wallet file, and was just showing a blank interface.. I was able to find my wallet file on my hard drive, and also having it backed up on my drive saved me from having a heart attack. I have no idea why it didnt load up my wallet as it always does when I open multibit client..
I have a cpl quick questions while Ive got your attention

I was originally using Multibit V 0.4.14, but have recently downloaded Multibit 0.5.9 SnapShot. Is it safe to just delete the previous Multibit Version 0.4.14 since I no longer user it, and I used 0.5.9? And since I have my wallet.file and Keys backed up onto two seperate usb drives, can I delete my wallet.file from my computer hard drive, so that in the case my computer was accessed by a criminal, they wouldnt have access to my funds? And when I needed to make a purchase or move bitcoins into my wallet, I could just stick in the USB drive and complete the transaction..? Would I create any problems by going ahead and removing the wallet file from my Laptop hardrive? or should I just leave it there? Thanks in advance, I appreciate all the help, and info. Ive come a long way in just a few months, all thanks to this site and the helpful members.

[jim618]

Hi Shkiser,

You can delete the old installed version of MultiBit yes.

Now that the wallets keep track of the last block they saw and get synced automatically it is practical to have wallets only on a USB drive. Like you say, that way if your laptop gets stolen/ accessed there is no wallet on it.

The main thing is to make sure you either close MultiBit or close the wallet using 'File | Close Wallet' before removing the USB drive. This is to make sure any information gets written to the USB drive cleanly.

[shkiser]

Hi Shkiser,

You can delete the old installed version of MultiBit yes.

Now that the wallets keep track of the last block they saw and get synced automatically it is practical to have wallets only on a USB drive. Like you say, that way if your laptop gets stolen/ accessed there is no wallet on it.

The main thing is to make sure you either close MultiBit or close the wallet using 'File | Close Wallet' before removing the USB drive. This is to make sure any information gets written to the USB drive cleanly.

JIM thank you for all the info you've provided me with. I sincerely appreciate you taking the time to answer my questions. Really thankful for multibit and the knowledgeable, and helpful techs that are here to help out multibit users.

[jim618]

No problem - I figure we are all still learning what the best way of using and securing bitcoins is.