I encountered a serious huge bug!...

[inshion]

Today I used vbox as usual.
After some upgrade of the ubuntu in vbox ,I took a SNAPSHOT. It worked well.
Then, I tried to DELETE an earlier SNAPSHOP via the snapshots manager UI, I clicked the DELETE menu item and started to wait.
Minutes later, some error message box displayed(I forgot the content), and I just closed the box.
Then I found that the virtual machine fatally be not able to start!
the error message is something like this(attachment pic1):

pic1

pic2012-04-13-153332000[1].png (17.79 KiB) Viewed 1469 times

I didn't know why so I opend the Ubuntu32.vbox file to check.
After I opend it, I was so shocked that the file is not a completed file!
The last 4 lines were:
<Guest memoryBalloonSize="0"/>
<GuestProperties>
<GuestProperty name="/VirtualBox/GuestInfo/Net/1/Status" value="" timestamp="1333802363828125002" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/1/V4/Broadcast"
and thereis nothing after them...obviously that should not be the end of the xml file!
this is the picture(attachement pic2):

pic2

pic2012-04-13-155216000[1].png (17.32 KiB) Viewed 1469 times

SO,now I can use none of the snapshots(picture below), I am so sorrowful and frustrated.

pic3

pic2012-04-13-155355000[1].png (13.92 KiB) Viewed 1469 times

[mpack]

Help us to help you. Upload pictures as local attachments, not offsite links. Even if you were allowed to post them, I for one have no intention of clicking unknown links!

[inshion]

Help us to help you. Upload pictures as local attachments, not offsite links. Even if you were allowed to post them, I for one have no intention of clicking unknown links!

sorry I didn't know that user can upload attachement...I hope you can see them now...
thank you

[mpack]

First thing, create a backup of that VM folder so you can't make anything worse.

After that, the first thing I would try is looking in the VM folder for alternate versions of the .vbox file. Ideally there is a file called <vmname>.vbox-new, (or vbox-tmp, I rarely see this so I don't remember), then try renaming that file to ".vbox" and see what the result is.

Failing that, there should be a file called <vmname>.vbox-prev, you can try renaming that. This is less ideal because it's an older version, but worth a try.

If you were using VDI (VirtualBox's native disk image format), then there are things you could have tried after that, but you weren't, so you can't.

[inshion]

First thing, create a backup of that VM folder so you can't make anything worse.

After that, the first thing I would try is looking in the VM folder for alternate versions of the .vbox file. Ideally there is a file called <vmname>.vbox-new, (or vbox-tmp, I rarely see this so I don't remember), then try renaming that file to ".vbox" and see what the result is.

Failing that, there should be a file called <vmname>.vbox-prev, you can try renaming that. This is less ideal because it's an older version, but worth a try.

If you were using VDI (VirtualBox's native disk image format), then there are things you could have tried after that, but you weren't, so you can't.

I looked up all the system, there is no any .vbox-new or .vbox-tmp file.
And I checked .vbox-pre file, it is also broken:

pic2012-04-13-1835454.png (6.95 KiB) Viewed 1456 times

[mpack]

If I were you I would run chkdsk on the host drive, because you seem to have suffered corruption of multiple files, including files that were not even opened when VirtualBox was running.

ps. Several of the files you have uploaded are actually text files. Those are best uploaded as text attachments (add a .txt extension to ensure the file type is recognized and accepted). Not only is the original text more complete and useful, it also takes less space to store.

[mpack]

The only solution I can think of for you to try is to create a dummy VM, add all of the .vmdk snapshots to it, starting with the oldest. Then see if VirtualBox will let you do a "VBoxManage clonehd" on the newest snapshot file. If it works it should merge all the snapshots into a single VDI (using --format if you want something other than VDI). You would then need to build a new VM around the cloned disk.