My last build failed upgrade to TeamCity Enterprise 9.1.6 (build 37459).
The error is service wide: System.MissingMethodException: Method not found: 'System.String System.String.Format(System.IFormatProvider, System.String, System.Object)'
I haven't change build configuration, and previous TeamCity build after rollback works fine.
The solution is for FW 4.0.
Target server for my service runs FW 4.5.2.
For previous build dotPeek shows
For failing build it shows
as if it is build for 4.6, see https://msdn.microsoft.com/en-us/library/dn906224(v=vs.110).aspx.
How to fix this?