I've been using FM Developer 5.5 for several months under Mac OS 10.15 and now under 10.2. Unfortunately, I experience fairly regular crashes when using the Developer Tool to make runtime solutions.
For 10.2, I wiped my hard drive clean and did fresh installs of FM 5.5, and still experience periodic crashes. After a crash, I trash all of the FileMaker-related preference files, restart, and eventually crashes disappear for a while.
I've attached a crash log on the outside chance that someone might be able to interpret what is going on.
Thanks.