No desktop after VM transfer

[Jess]

Transferred my virtual machine from an old to new laptop. The machine works fine on the old laptop but boots into an internal error message to do with compiz on the new laptop ("Sorry Ubuntu * has experienced an internal error" /usr/bin/compiz). I can see my desktop background but nothing else and I can enter terminal via Alt+Ctrl+F1 but not +T.

I tried various solutions suggested online which were mostly to do with updates and ensuring 3D graphics was checked. I then decided it was probably a problem with my Guest Additions (because I had struggled to install these) so I removed them, but it didn't help.

I then decided to "Export Appliance" (creates .ova) on my old laptop and "Import Appliance" on the new, just in case this would help. I get "Failed to import appliance" and VBOX_E_FILE_ERROR in the details.

Having decided it was easier to give up and start again from fresh, since this is a relatively new VM, I installed Ubuntu 14.04, started the machine and experienced the same error.

Any suggestions would be greatly appreciated.

This is a nice description of the problem:
itsfoss DOT com SLASH how-to-fix-no-unity-no-launcher-no-dash-in-ubuntu-12-10-quick-tip
I tried their fix, except Ctrl+Alt+T also doesn't work so in the terminal Ctrl+Alt+F1 produces, and it didn't work. I've tried countless other fixes too. Also my "Insert Guest Additions" button produces an "Unable to insert" error (Force Unmount does nothing).

[mpack]

Transferred my virtual machine from an old to new laptop.

How? I see that you tried export/import as your second attempt, but what did you do first?

For what you should have done, see Howto: Move a VM.

If you want to continue this discussion then provide a VM log file, and give the precise wording and context of any error message seen: Minimum information needed for assistance.