I have been having trouble when put into the test realm during the Norushen encounter. Once inside, my game freezes. It is pretty much an add-on problem and I wonder if anyone else have experienced this and located a possible offending add-on. Looking at the official forums suggest this also affected a number of people as well.
I am using a collection of add-on, not many by most standard. Most are typical common add-ons. Grid, Bartender, Titan Panel, Altholic, GTFO, Ice HUD, MSBT to name a few. I don't have the full list. I have tried starting to isolate the add-on but with limited playtime, it is a rather slow process.
The only add-on that might be unusual is Spartan UI. This primary arranges my UI in a certain way rather than manually moving them around. It is not really a raid related UI.