multimonitor fails to render the screen correctly when both Xmir and X are running and produces "cannot switch monitor configuration" error notification

[Eleni Maria Stea]

How to reproduce:
Boot ubuntu and login to unity having both monitors plugged.
Start xserver (with startx)and enter another DE. - i started xfce
Change the display settings to match the unity display settings in the other DE
Unplug and plug the 2nd monitor while on X DE
Switch to the unity tty (ctrl alt f7 in my case)
You should get the error.

When I ran the screenshot program I got a crtc error notification (see the screenshot).

[Eleni Maria Stea (hikiko)]

and a more descriptive picture of my two monitors

[Daniel van Vugt (vanvugt)]

Could be related to the issues causing bug 1216748 too.

[Eleni Maria Stea (hikiko)]

After latest I can only reproduce it when I configure the multimonitor and then I unplug and plug the monitor while I am on X graphics vt (vt8 in my configuration). If I plug and unplug the monitor while I am on Mir graphics vt (vt7 in my configuration) everything is rendered correctly.

[Daniel van Vugt (vanvugt)]

XMir 1.0 (the old Xorg extension) is now deprecated and is not being maintained or fixed. It is replaced by the new 'Xmir' binary (package 'xmir') introduced in Ubuntu 15.10 wily.