Do you use VirtualBox or other software for virtual machine?
Yes. I use VirtualBox
What operating systems are on the host and guest machines? Which Linux?
The host machine is Windows 10. The guest machine runs Linux.
Have you installed the VM guest additions?
Yes it should be installed.
What UGENE version do you run?
v33.0
Which PDB file do you open? Could you please send it to us?
These are the sample pdb files provided by ugene. I tried all of them
If possible, you might also send us the exported appliance of the virtual machine.
This would be the .ova file, correct?
Is "3d" structure object is shown in bold in the Project View?
No it's not bold