WCF Service returning “requested service '…' could not be activated” the first time it's accessed from an MVC site

Question

We have a WCF service (with no security) that is being accessed by an MVC3 website.

On the developer machines we have no problems with it but when our TeamCity setup bui

Answer 1

I've hit the same "Could not load type 'System.Runtime.CompilerServices.AsyncStateMachineAttribute'", which I found out was because I had built my application using VS 2012 RTM, but then tried to deploy it on a machine that only had 4.5 Beta. The AsyncStateMachineAttribute is a new type added after Beta.