Broken with 12/10/2019 update

[medic3447]

No longer works after 12/10/2019 update. Causes "unknown API" error.

[ulonger]

Found the same issue, looks like the API is changed.

WoW Classic 1.13.3 Patch Notes

The lua API has been modified to prevent some addons from using communications channels in ways that are contrary to the spirit of the game.