This is the relevant error log for this crash:
EXCEPTION: ERROR in action number 1 of Step Event0 for object par_Toolbar: Variable Index [0] out of range [0] - 31.106546(106546,0)------------------------------------------ STACKTRACE: >> gml_Script_editor_RecompileScripts (line 2) >> gml_Object_par_Toolbar_Step_0 (line 46)