Unity does not release ports?

Unity Version: 4.5
Everytime I started a Server and started a Match (new scene will be loaded…) and then quitting it throgh the playmodebutton - next time I cant start a server because unity is using the ports. I get this error:

Failed to initialize network interface. Is the listen port already in use?

and

It’s not possible to register a host until it is running.

Can anyone help me?

I also tried to do Network.Disconnect and MasterServer.UnregisterHost in OnApplicationQuit-Function - but that does not work…

I searched for this issue - there was one who said that failed SQL connections can be a problem - but that didnt help too

And sorry for my english - Iam from Germany ;D

I’ve had this problem for months now, and finally figured out what was wrong (at least for me). For some reason Unity’s Shader Compiler was hanging after playtesting the game. Every subsequent time I tried to initialize a server I’d get the port in use error. Going into task manager and manually ending “UnityShaderCompiler.exe” releases the port, for whatever reason.

I found that if I open Unity, initialize once, back out, and then kill the shader compiler process, I don’t have any subsequent issues until I restart Unity again.

Hope this helps someone. I’ve been banging my head on this problem for monts now.

I hope that unity will fix that… otherwise I must find a solution, or I will load my backup project in unity 4.2