Even more info is available beyond what the patch notes tell for UI changes. Drysc posted a list of the overall changes to the UI on the PTR forums. Lua errors are no longer shown by default, but you can set the scriptErrors cvar to 1 to enable them. It is recommended that AddOn authors and testers leave this turned on so you can catch problems in your AddOns. This is implemented by code in …
Original post by (Kody)