WotLK The problem with the dungeon

[Krang87]

Hello, I'm playing the server Lordaeron , my game class priest , my gaming nickname ( Zebul ) .
When I came for the first time the dungeon (Deadmines) after killing final boss ( van Cleef ) I have lost the Internet connection.
And in the end, during the first murder of the boss, I could not take a quest item from boss body (An Unsent Letter) which opens the chain of tasks.
I went to this Dange 4 more times , and never from the final boss quest item (An Unsent Letter) was not in the lut .
Help me please .

[Krang87]

The topic is not relevant, the problem is eliminated