Unhandled Activation Error

I receive this error when I try to login/connect my account in xamarin studio. Please help because I cant publish or debug my app.

System.Exception: Could not load machine data: Unhandled Exception: System.TypeInitializationException: An exception was thrown by the type initializer for MTouch ---> System.TypeLoadException: Could not load type 'Typespec 0x1b0001cc' from assembly 'mscorlib'. --- End of inner exception stack trace --- [ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: An exception was thrown by the type initializer for MTouch ---> System.TypeLoadException: Could not load type 'Typespec 0x1b0001cc' from assembly 'mscorlib'. --- End of inner exception stack trace --- at Xamarin.Components.Ide.Activation.ActivationHandler+c__AnonStorey6A.<>m__E9 (System.Threading.Tasks.Task

1 t) [0x00045] in /Users/builder/data/lanes/monodevelop-lion-license-sync/c5f82958/source/md-addins/Xamarin.Ide/Xamarin.Components.Ide/Activation/ActivationHandler.cs:672 
      at System.Threading.Tasks.TaskActionInvoker+FuncTaskInvoke

2[System.Int32,System.String].Invoke (System.Threading.Tasks.Task owner, System.Object state, System.Threading.Tasks.Task context) [0x00000] in /private/tmp/source/bockbuild-xamarin/profiles/mono-mac-xamarin/build-root/mono-3.2.5/mcs/class/corlib/System.Threading.Tasks/TaskActionInvoker.cs:331 at System.Threading.Tasks.Task.InnerInvoke () [0x0000b] in /private/tmp/source/bockbuild-xamarin/profiles/mono-mac-xamarin/build-root/mono-3.2.5/mcs/class/corlib/System.Threading.Tasks/Task.cs:503 at System.Threading.Tasks.Task.ThreadStart () [0x00097] in /private/tmp/source/bockbuild-xamarin/profiles/mono-mac-xamarin/build-root/mono-3.2.5/mcs/class/corlib/System.Threading.Tasks/Task.cs:404