Get “Internal error in the expression evaluator” on “Add watch” function when trying to debug WCF service code (MSVS 2013)-open source projects tj/watch

Few days ago I moved my solution to MSVS 2013. It works fine except one thing: when I trying to debug code of my WCF service it works, but when I want to watch state of any variable it says: “Internal error in the expression evaluator”. Add watch function works normal on client side, but in service code it broken. I’m trying to debug my own WCF service running on the localhost. Could you help me, how to repair this?

Here MSVS info: Microsoft Visual Studio Professional 2013 Version 12.0.30110.00 Update 1 Microsoft .NET Framework Version 4.5.51641 OS: Windows 8.1