[Josh Pratt]

Finally ran this down, posting in case it saves someone else — the “Exception: std::exception, what:Failed to create transform rule” error may have nothing to do with your script, bins, or media.

Media Composer ships with an embedded Elasticsearch service that ScriptSync AI depends on. On my failing machine (macOS, MC 2025.12.1), that service was crash-looping silently in the background — restarting and dying every ~10 seconds.

How to check: open Terminal and run

tail -50 /Users/Shared/AvidMediaComposer/Search/logs/elasticsearch.log

If you see “java.lang.RuntimeException: can not run elasticsearch as root” repeating, you’ve got the same problem. Avid’s installer left a root-level LaunchDaemon (/Library/LaunchDaemons/com.avid.elasticsearch.plist) that launches the search service as root, which Elasticsearch refuses to run as. Newer installs also add a user-level LaunchAgent at /Library/LaunchAgents/com.avid.elasticsearch.plist — the fix is to disable the root daemon and let the user agent take over:

1. Quit Media Composer

2. sudo launchctl bootout system/elasticsearch

3. sudo mv /Library/LaunchDaemons/com.avid.elasticsearch.plist ~/Desktop/

4. sudo rm -f /tmp/elasticsearch.out /tmp/elasticsearch.err (root-owned logs that block the user agent from starting)

5. sudo chown -R $(whoami):staff /Users/Shared/AvidMediaComposer/Search

6. Log out and back in (or: launchctl bootstrap gui/$(id -u) /Library/LaunchAgents/com.avid.elasticsearch.plist)

7. Verify with: ps aux | grep elasticsearch — the server process should now be running as your user, not root

After that, ScriptSync AI worked immediately for me. It seems to depend on install/upgrade history rather than MC version — I had an identical MC build working fine on another Mac, which is what let me diff the two machines and find this. Worth reporting to Avid support if you hit it so it gets a proper bug ticket.