Steps to reproduce:

1. Download attached project and open Unity project located at root/RemotingTest
2. Run root/RemotingTestService/RemotingTestService/bin/Debug/RemotingTestService.exe
3. Back in Unity, run scene "test"
4. Press A and notice that in running exe remove event is triggered
5. In hierarchy, select GameObject and click on Initialize script's gear icon
6. Select "Initialize Sink"
7. Repeat step 5 and select "Link Sink"
8. Notice exception:
UriFormatException: Invalid URI: Invalid port specified.
System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke (System.Runtime.Remoting.Proxies.RealProxy rp, IMessage msg, System.Exception& exc, System.Object[]& out_args) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Runtime.Remoting.Proxies/RealProxy.cs:231)

Reproduced with: 5.3.3p3, 5.3.6p3, 5.4.0p4, 5.5.0b1
Not reproducible: 5.3.3p2