Patch Day

[Cairenn]

We have deployed a client-side change that should improve performance when large numbers of players are gathered in a small area of the world. No other changes are included with this emergency patch - Blizzard Patcher

And, as a reminder, there is an option built into WoW to disable the version checking and allow you to play with interfaces (at your own risk) that weren't specifically designed for the version you're using. Here is how to do it:

Open WoW and get to Character Select
Click on "Add-Ons" in the lower left corner of the screen
At top there is a checkbox for "Check Version Compatibility" - turn it off

Its better to use this method than to modify the .toc files yourself, because you will know which files are modified and which are not when you turn version checking back on.

Here is a link to the official thread on this: Link!

Be sure to check back over the next few days to get the updates when the author(s) of your interface(s) make updates