KM freezes in Catalina 10.15.7, but oddly enough only here:
1.- Open KM 9.1
2.- Make sure KM is not in Edit mode
3.- Do a search in KM 9.1 for something like "math"
4.- Select a disabled item from the results (I selected the Napkin macro, which is inside a "Work in Progress" folder)
5.- Close KM using CMD-W
Result: KM freezes, have to force quit
Have not checked thoroughly with other macros, but oddly enough happens only with this macro