Grimes's post in ME not allowing changes to aircraft only was marked as the answer
2021-07-17 04:40:57.515 ALERT LUACOMMON: Error: GUI Error: [string "./MissionEditor/modules/me_aircraft.lua"]:923: cart has no default task!
cart is the unit typename. It is something from one of the mods you have installed. Probably best to figure out which mod is at fault and alert whoever made it and uninstall it in the meantime.
Grimes's post in Combined Joint Task Forces Bug was marked as the answer
You have historical mode on. Its a filter that limits the available units for a given country based on the year. Combined Task Forces don't have dates setup for any unit, thus it is empty except for the unit you placed. Click the watch icon at the bottom to turn off historical mode.
Grimes's post in [REPORTED] X: COCKPIT PARAM IN RANGE only accept integer values was marked as the answer
Thanks for the info. It is reported.