Comment 12 for bug 1790525

Reinstalled current libmutter.
With dual monitor horizontal aside this gives
Feb 1 22:26:58 Gert2 gnome-shell[1038]: Failed to allocate texture: Failed to create texture 2d due to size/format constraints
Feb 1 22:26:58 Gert2 gnome-shell[1038]: CoglError set over the top of a previous CoglError or uninitialized memory.#012This indicates a bug in someone's code. You must ensure an error is NULL before it's set.#012The overwriting error message was: Sliced texture size of 2560 x 1024 not possible with max waste set to -1

Logon-session crashes before showing logon-screen.

Installed proposed version:

apt list libmutter-3-0
Listing... Done
libmutter-3-0/cosmic-proposed,now 3.30.2-1~ubuntu18.10.3 i386 [installed]

Problem is solved by proposed package. No new other problems detected.