@beeblebrox
I actually just found the solution thanks to this gitlab issue ((Star2lte) Trebuchet Crashes When Trying To Retrieve Running Apps When No Launcher Is Set As Default (#4520) · Issues · e / Backlog · GitLab).
Trebuchet crashes because there is no default launcher selected in the default apps. So just set up a default launcher app in Settings > Apps > Default apps and it will fix the problem.