I do not know for sure, but you may have to do with the new changes, concerning "Web Extensions". And the end of XPCOM / XUL support. It would not be the first addon to Firefox with this problem.
Dear friends, I have a problem. I need to copy multiple links to the clipboard. This is the code: VERSION BUILD=7401110 RECORDER=FX SET !EXTRACT_TEST_POPUP NO SET !ERRORIGNORE YES SET !TIMEOUT_STEP 0 TAG POS=1 TYPE=NOINDEX ATTR=TXT:http* EXTRACT=HTM TAG POS=2 TYPE=NOINDEX ATTR=TXT:http* EXTRACT=HTM ...