Automatic 5.2.8 update - can't open old snapshot - NS_ERROR_FAILURE (0x80004005)

[theboxuser]

Hey everyone,

My Linux mint 18.3 system recently automatically updated virtualbox (previously 5.1 was installed).

As a result I can't restore my main snapshot anymore (which I desperately need). After the restore-bar reaches 100%, it crashed with the message

Result Code:
NS_ERROR_FAILURE (0x80004005)
Component:
SessionMachine
Interface:
ISession {7844aa05-b02e-4cdd-a04f-ade4a762e6b7}

I uninstalled virtualbox and reinstalled 5.2.8 including the extension pack and guest additions.

Still, same error.

Interestingly, I can reboot the virtual machine, but I can not restore the snapshot.
The log file shows why. While the reboot does not show an error message, the restoration crashes with:

00:00:16.512605 OpenGL Warning: Assertion failed: pContextInfo=0, file /home/vbox/vbox-5.2.8/src/VBox/HostServices/SharedOpenGL/crserverlib/server_main.c, line 2316

Does anyone have any idea how I could tackle this issue?
Any help would be appreciated.
Thanks.

Interestingly though, I can reboot the

[mpack]

Please provide a VM log file. With the VM fully shut down, right click it in the GUI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.