`window.alert` in a UXP plugin crashes InDesign

Fair enough (thank you for looking into this!), but in that case, I would suggest that it shouldn’t crash InDesign but immediately abort with an error message in the console instead. I remember that it was mentioned during office hours at some point that this is an essential piece of functionality, especially for existing InDesign devs (who might try to use it and, with the intermittent behavior, maybe not notice that it doesn’t work consistently)…