As of the 6/16/2022 update, the latest garry's mod update breaks the main menu if you already had the new Workshop Collector installed before the update. Delete garrysmod/garrysmod/lua/menu.lua, verify your game cache, and re-add the include( "workshop_collector_menu.lua" ) line to menu.lua in order to fix the issue.

If you are installing this beyond that point, you should be fine.