I guess this is a known issue with the following exception:

Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'svcutil, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. Strong name validation failed. (Exception from HRESULT: 0x8013141A)
File name: 'svcutil, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' ---> System.Security.SecurityException: Strong name validation failed. (Exception from HRESULT: 0x8013141A)
The Zone of the assembly that failed was:
MyComputer

As a temporary fix you can mark the assembly to be skipped for strong name validation as follows:

sn.exe -Vr svcutil.exe