LK DC and WoW Errors

As title says how to fix this ...
This thing is 110% from server side as i had not a single problem on any other wotlk servers
Also my pc and internet is good enough to launch 20 clients at same time .
I've lost many items due to that issue any fix for that?
LK dc happens either after frostmourne or on lk dead movie while errors can happen anytime but what i observed for last 2 years they occur only out of combat (any combat ANY prevent error never had any during any encounter)

Think common way to fix the movie DC/crash is to delete the movie from game files.