virtualbox.org

Packet Tracer is Cisco's network simulator software. It does not exist on CentOS, my host OS, so I installed it onto my Windows 10 guest. It starts flawlessly but upon login to Cisco Network Academy, I get a blurred window, it seems that the window shows a part of the video buffer from other parts of the software. It freezes there, although I can close that window. But upon another try it comes again.

Is this a Packet Tracer or a Virtualbox or Windows 10 problem?

Only thing that I could think of is video capabilities in a VM.

Start the VM from full power off, not save-state. Run until you see the problem happen, then shut down the VM from within the VM OS if possible. If not possible, close the Virtualbox window for the VM with the Power Off option set.

Please right-click the VM in the main Virtualbox window's VM list, choose Show Log. Save the far left tab's log, zip the log file, and post the zip file, using the forum's Upload Attachment tab.