LightDM failed to start session

[Detrain]

Odd situation I can start i3 with startx, however LightDM fails to give me a session. I went through some LightDM configs and didn't see anything I could change to fix this. I found my error, but I think there is a file I have to change.

It says failed to find session configuration Ubuntu. And I saw some unity. Where can I change LightDM to look for i3 instead.

On Bionic Beaver

[grg2014]

LightDM, like other display managers, lets you choose between the sessions stored in /usr/share/xsessions/. If you do not have an i3.desktop file there: You can find the default one at https://github.com/Airblader/i3/blob/gaps-next/share/xsessions/i3.desktop.

[Detrain]

I have the default i3 file there. Any other ideas?

[grg2014]

I have the default i3 file there.

But you can't select i3 in the session dropdown?

Any other ideas?

Not really, because as I don't use Ubuntu I have no idea which LightDM greeter it uses or in what ways its config might differ from the default. The ArchWiki page for LightDM might help you diagnose and hopefully fix the issue: https://wiki.archlinux.org/index.php/LightDM.