There are two inner exceptions,
both with same message: “The
current type, XXXXXXXXX, is an interface and cannot be constructed. Are you missing a type mapping?”. This is
part of the content of tracelog of WCF.
<ExceptionType>System.InvalidOperationException, mscorlib, Version=18.104.22.168,...
We think that is some type of bug in the Unity application block (Microsoft.Practices.Unity.dll v1.2).
Due to the exception arrise only some times, it's impossible to identify
behavior, but we think that only happens when unity try to resolve the first
dependency. Our mappings are in .Config file and we think that if we do the mapping register in the code on run time perhaps this solutions the problem but we can't do this for now.
Sorry for not give you more info and thanks for the reply.