Bug: Cannot save Trello automation rule with LanguageTool Firefox plugin enabled.

[ErikBrendel]

I use the LanguageTool Firefox extension. When trying to edit automation rules on Trello (see attached screenshot and video), the plugin correctly attaches to the textarea. When trying to save the modified automation rule, it crashes with an error of "CANT_PARSE_COMMAND". It seems like the Trello script has troubles correctly accessing the content of the textarea. Disabling LanguageTool on that page resolves the problem, and everything works again as expected.

I already contacted the Trello support, and they suggested getting in touch with the LanguageTool developers instead.

Trello ticket discussion: https://getsupport.atlassian.com/servicedesk/customer/portal/58/TRELLO-98597
Screenshot:

Screencast:
https://user-images.githubusercontent.com/11018565/148227335-a34965ef-1bc4-4fbd-9964-44df7d91bbb6.mp4