1a) I've set AC to G (for Class G), so it's not an unknown or invalid type, but it still doesn't change colour.
1b) Well I copied the airfield used in the thread I linked above, EGTF, and my txt (which I named egtf.txt) has only this inside it;
AC G
AN Fairoaks ATZ
AL SFC
AH 2080ALT
V X=51:20:53 N 000:33:31 W
DC 2
I've tried doing the SB and SP commands, but it never changes anything
Under 'Scenery Library' the only options are;
"1 Microsoft Flight Simulator X"
"2 X-Plane 11 (empty, no simulator)"
"Navigraph - AIRAC Cycle 1801"
"Airspace Libraries"
"Load User Airspaces"
"Validate Scenery Library Settings"
"Load Scenery Library"
When all the options under Airspace Libraries are deselected, the airspace in question still does not disappear
So yeah, I have no idea why it won't change colour and won't disappear haha. Any help is hugely appreciated