To use Zotero with Microsoft Word 16.44 or later on an Apple Silicon (M1) Mac, you must be running Zotero 5.0.95.2 or later. A bug in macOS prevents earlier versions of Zotero from communicating with Word.

• If you haven't yet upgraded to Zotero 5.0.95.2 or later, you should update via Help → “Check for Updates…”.
• If you've upgraded to Zotero 5.0.95.2 or later:
  • If you're still running Word 16.43, you should upgrade to the current version of Word.
  • If you previously set Word to open under Rosetta to work around this bug, you should select Word in Finder, go to File → Get Info, and uncheck “Open using Rosetta”, and then restart Word.
• If you're not yet able to upgrade to Zotero 5.0.95.2 or later, you can work around this bug by a) downgrading to Word 16.43 or b) setting Word 16.44 and above to open under Rosetta by selecting Word in Finder, going to File → Get Info, and checking “Open using Rosetta”.

Zotero hasn't yet been ported to Apple Silicon, so it runs under Rosetta on M1 Macs. Prior to Word 16.44, Word also ran under Rosetta, and Zotero's Word integration worked without problems.

Starting with Word 16.44, released on December 15, 2020, Word runs natively on M1 Macs. Zotero uses Apple Events to communicate with Word, and due to a bug in macOS (filed as FB8943158), trying to pass 2048 (2¹¹) or more characters of text between a Rosetta app and an Apple Silicon app via an Apple Event results in a freeze. The same thing happens trying to pass 2048 characters in an AppleScript from Script Editor to TextEdit when Script Editor is set to run under Rosetta, or vice versa. It doesn't happen when both apps are running under Rosetta, as was the case before Word 16.44.

Starting with Zotero 5.0.95.2, Zotero automatically starts an intermediate service in native mode to forward messages between Zotero running under Rosetta and Word running natively.

If you have questions about this issue, let us know in the relevant forum thread.