Reproducible Bug in Keyboard Maestro V10

[ComplexPoint]

Might there be a disabled font, as discussed below ?

Keyboard Maestro 10 Crashes

If the Cochin-Italic font is disabled, Keyboard Maestro will crash as soon as it tries to display the Variables (x) icon (which appears it lots of places). Most probably this is your issue - it is fixed for the next version, and you can enable the Cochin-Italic font to resolve the issue.