Sunk in harbor

[fvd]

I just transfered from Brest to La Spezia, my boat is a type IX
When i started a new mission something strange happened.
My boat was shaking forward and backward and the rear end of the boat seemed like it was inside the wall of the dock.
When i started the propellers i got severe damage untill the boat sunk.

What can i do about this?
How is it possible that my boat is stuck inside the dock wall?

Thanks Kaleun's!
Regards,
fvd