Update:
Crashes still happening. Logs show nothing new. Can recreate fairly consistently. When attempting to highlight and select more that one effect in a sequence a few of the slide bars (color, cycle count or whatever effect is selected start darting back and forth and then I get the non-response hang. Have uninstalled xlights and reinstalled 64 bit version. Same issue.
Windows 10/home 64 bit
Checked Windows Event and security logs and only generic failure info recorded. Nothing specific or actionable.