The game loads for some time showing the indicator on the bottom right of the black screen, then it sometimes shows the main screen for less than a second and crashes in the next moment.

It used to work before, but stopped working some weeks ago, possibly due to an update of Debian 11 which has not been released yet, and therefore is still receiving major updates e.g. of drivers.

Tried multiple solutions such as setting PROTON_NO_D3D11=1 PROTON_NO_D3D10=1 or PROTON_NO_ESYNC=1, but none worked.

When running steam from the command-line, this suspicious error message gets printed:

[1231/112326.684:ERROR:angle_platform_impl.cc(36)] rx::SwapChain11::resetOffscreenColorBuffer(278): Could not get offscreen texture shared handle, HRESULT: 0x80004001