AlmaLinux 9.1 Guest, black screen after login

[Mats62]

Hi. In the attached archive logFilesWithAndWithoutTheBlackScreenAfterLogin.zip are VBox logfiles, two copies each, from booting a VM and logging in to it. The files starting with an underscore are the same files as the ones without the "_", just with the most obvious parts of lines edited that will differ, due to timestamps, for slightly easier line-by-line comparison.

In one case I can log in, in the "broken case" it hangs with a black screen after I submit the password. (and I then forcefully power it off) If I wait a minute or so, before powering off, the login-screen comes back.

The difference between working and not working is one single line added in /etc/gdm/custom.conf in the guest:
[security]
#DisallowTCP=false
If I uncomment the line with "DisallowTCP=false I can no longer log in. (but if I set DisallowTCP to "true", I can also log in)

When the problem is present, /var/lib/gdm/.local/share/Xorg.0.log says "no screen found".

The same setting causes no issue on bare-metal installations with the same package-set.

The differences in the logfiles starting around line 1860 seem to be showing something, but I don't know what they are trying to tell me.

I'm not 100% sure, but it could be that this started to happen after a Win11 update to 23H2 on the host, the logs seem to suggest that the GAs are disturbed by that setting in custom.conf.

Any ideas?
thx in advance.... / Mats

[Lisa Miller]

Try to set the VGA Memory size of the VMs, to the same size which your real hardware have.