Virtualbox not working on 5120*1440 screen

[recluce]

Virtualbox does not run on this resolution (6.1.8 on Arch Linux, installed from tar ball), Cinnamon or LXQT desktops, NVidia Graphics - it cannot open its GUI. It works on the same setup with the resolution scaled down to 3840*1080. The GUI can be brought up by starting Virtualbox in the lower resolution and then changing back to 5120*1440, GUI works normally at this point. However, when you enlarge the Window of a virtual machine (tested with a Windows 7 VM, guest additions 6.1.8 installed), the VM closes unexpectedly if you increase the window size above 3840*1080.

I found no solution to this except using VMware Workstation.

Not sure if this design limit is due to the 256 MB video memory limitation or what the issue might be. I would love to return to Virtualbox, but I guess that users on Ultrawide screen are to small a minority for Oracle to care.

[fth0]

Not sure if this design limit is due to the 256 MB video memory limitation or what the issue might be.

On my iMac with a 5k Retina display (5120x2880), I can successfully run a Linux VM fullscreen with 128 MB of Video Memory configured. While the VM is running, I can change the resolution back and forth without any problems, also switching from and to Full-screen Mode works as expected. The only problem I have is when starting the VM in Full-screen Mode: Then the display stays black, and I have to leave and reenter Full-screen Mode (2 * HostKey-F) to get the screen contents. It doesn't matter to me, because I usually run VMs with 150% - 200% scaling, though.

If you want me to have a look, please reproduce the problem, shut down the VM, zip and post the corresponding VBox.log file, accompanied by a short description of what screen-related actions you tried.