virtualbox.org

I was having this same issue. I saw the comments on the shared folder, so I checked to make sure the drive I'm sharing to the VM was mounted on my Ubuntu host, then checked the contents and I could see everything on my host. Started the VM after that and it worked just fine.

This is happening to me and I also had changed something about the shared folders--changed one that was marked as auto. Maybe it did not save correctly the last time I shut it down and now there is some kind of inconsistency.
I have Windows 7 host VirtualBox version 4.0.10 r72479 and the guest is Windows Server 2008. I believe I did install the newest guest additions, though I'm not certain.
Log file is attached. This is without messing with the XML file.
None of the above suggestions worked:
1. messed with SharedFolder entries in XML file. I have a bunch of those presumably because I have several snapshots.
2. created a snapshot from the saved state and still get same error on open.

I also tried just deleting all of the <SharedFolder> sections out of the XML file. That did nothing for me.
I then tried to revert to an older snapshot and it still didn't work! I realized that I had not restored the backup of the XML file before doing that; so I tried to do that, but now my drives and snapshots are in a different state; so doing that made the whole machine inaccessible. So, I restored the xml-prev file and I'm back, but still can't boot up again because of the error discussed here and have no shared drives.

{edit fixed!!}
I finally got my machine back up and running by editing the .xml file which reflects the current reversion to a previous snapshot, but editing to add the SharedFolders sections all back in, except for one thing. I had two shares all the way through up until the last two snapshots (or the snapshot and save before I turned that save into a new snapshot) where I had added a new share. So, I just deleted that extra share so that the most recent saves looked like the previous saves (save/snapshot that is). My machine restored, though I lost a save state.

Well, I lost a lot of time with all of that. Maybe even if it does use a ton of disk space I should try to have a backup. But I thought that's what snapshots were for! Make backups of it still because in the three years I've been using VirtualBox, many improvements were made, but it remains unstable.

I had the same error with version 4.0.6 (even after upgrading to 4.0.12). I used Discard to reboot the machine (I didn't change snapshots). This then booted OK (except Ubuntu, the guest OS, said there was a problem with the shared folder, which I could choose to Skip). So that a relatively painless thing to do (like pressing reset when the computer has hung, messy but you don't lose what's on disk).

I ran across this issue today. The thing that mess it up for me was I deleted the folder that I had shared to my Guest via shared folder. After recreating the folder on the host, I was able to start the Guest from it's saved state. After that I remove the shared folder from the Guest.

Just to test that it will work moving forward, I saved the state and started it back up. All is working will now.

Same issue here with actual VB. That is really a pitty.

I am getting this error with one of my VMs too.

I migrated (copied) the VM (files) from one PC to other.
The old PC had Windows XP and Virtualbox 4.1.2 while the new has Windows 7 and Vbox 4.1.4.

After trying to run a powered on snapshot of the migrated VM, I get:

Failed to open a session for the virtual machine Windows XP za AV.

Failed to load unit 'HGCM' (VERR_INVALID_PARAMETER).

Result Code: E_FAIL (0x80004005)
Component: Console
Interface: IConsole {1968b7d3-e3bf-4ceb-99e0-cb7c913317bb}

I'll attach the log.

Install the Extension Pack or make sure you turn off USB2 in the guest settings Remove the shared folders in the guest settings and try again

The extension did not change anything, I still get the same error.

I can not remove the shared folders, because the settings button is disabled.

I created the missing shared folder on the host system and now the VM starts.

This is really a bad way to handle such a situation.
Either the missing folder should be ignored (not used for shared folder) or there should be an option to manually disable it (or maybe an option to create the missing folder). (by the latter I mean in the warning dialog)

One more thing. The VM starts but is frozen. I can not do any mouse or keyboard interaction (it is showing the WinXP desktop) and the system clock in the systray does not advance. I chose menu Machine / Reset and it rebooted.
But now it is since minutes on the boot screen (Windows flag on black background and the blue progress throbber).

I'll attach the logs for the "eternal boot" case (the VM is still running).

After a long time it booted.

I'll attach the logs, taken after closing (saving) this VM.

Only perform if you can afford losing any unsaved files.

1. Right Click on VDI which is throwing this error
2. Select Discard Saved State

Note - if you don't have this feature probably you might have to migrate to new VBOX v4.1.4

I ran into this problem recently. The VBOX file has consistent definitions for SharedFolders throughout and don't include definitions for the missing shared folder so editing the VBOX file won't work.
The situation is this. I defined a share (permanent IIRC) for a usb stick and mounted it in my debian guest. I told Win7 to eject the stick which it did quite happily (note the debian system still thinks it's mounted). I then snapshot the VM and close it. The VM now fails with this error after reloading the state. It will do this every time. Settings is greyed out so I can't fix shares but it doesn't matter because the share isn't defined.

If I plug the usb stick back in and restart the VM everything seems to be fine.

Whether or not yanking the usb stick out from under the guest OS is advisable or not is debatable. VB should probably be locking it until it is unmounted by the guest OS (assuming that's possible).

My work around is to not do this anymore.

sorry - I didn't remember correctly - The shared folder was for a TRANSIENT SHARE that was pointed at a USB stick.

Apparently these aren't maintained in the VBOX file (at least I don't see it).

Restoring the USB stick, starting the VM, changing the share to permenent, and closing the VM added the share to the Hardware section of the VBOX file only. None of the shared folder sections in the snapshot sections list the USB stick.

Removing the entry for the USB stick from the hardware section didn't help.