UIDesktopWidgetWatchdog::sltHandleHostScreenAvailableGeometryCalculated: 0x0 1920x1173

[burdi01]

Recently I migrated my multi-boot system from an i7-6700 to a Ryzen 9 3900XT.
Since then when VB is started under Slackware Current64 all VM's fail to start, whereas when VB is started under Xubuntu 20.04.1 these VM's start as expected.
The failure occurs very early in the start sequence: the big "starting arrow" remains shown and the system freezes all over. A hard restart is required.

From the VBox.log's it seems that the Slackware problem is:

GUI: UIDesktopWidgetWatchdog::sltHandleHostScreenAvailableGeometryCalculated:[[BR]]
 Screen 0 work area is actually resized to: 0x0 x 1920x1173

whereas the Xubuntu VBox.log reads:

GUI: UIDesktopWidgetWatchdog::sltHandleHostScreenAvailableGeometryCalculated:[[BR]]
 Screen 0 work area is actually resized to: 0x25 x 1920x1150

Note the "0x0" versus "0x25".

As via symlinks the VB settings and VM definitions are shared between the sundry Linux instances an error like a "leftover" file definition is highly unlikely.

Some other differences beween the VBox.logs are:
-- Xubuntu kernel 5.4.0-48-generic, Slackware 5.8.14-burdi64;
-- Xubuntu VB QT version 5.12.6, Slackware 5.6.1;
-- Xubuntu X release 12008000, Slackware 12009000;
-- Xubuntu loads a VMMR0.so, Slackware does not.

I started out with VB 6.1.14-140239. For Slackware I then tested VB testbuild 6.1.15-6.1.15-140809 asis with kernel 5.8.14-burdi64 and the same testbuild but patched (see #19845) with kernel 5.9.0-rc8-burdi64.
However the problem persists ...

[burdi01]

Please disregard.

[burdi01]

Please disregard

[burdi01]

This thread should be regarded as superseded by #20021