I am a newcomer with KB Maestro. I find that when I do one of the following things: 1. Quit KBM Editor, or 2. Close a Macro Palette, KBM seems to quit. I am not able to get any of the saved macros to run, using the triggers assigned, nor can I display any palettes. The only way to recover is to restart my computer (an iMac running High Sierra. So long as I don't do any of those two things, there is no problem running my macros.
Thank you for your comments. When I wrote my question, it looked like I had found repeatable actions that caused KBM to fail to work. Now, I am able to open and close Macro Group Palettes without causing the crash. Perhaps it had to do with intensive use of the Editor to create a large number of macros. I'll have to give it some time and observe over the next several days.