Add following configuration to your wcf service config. And see c:\log\Traces.svclog file.
My exception was throw for ;
There was an error while trying to serialize parameter
The InnerException message was 'Enum value '0' is invalid for type 'ThyCams2014.XrmBase.new_filingstatu' and cannot be serialized. Ensure that the necessary enum values are present and are marked with EnumMemberAttribute attribute if the type has DataContractAttribute attrienter code herebute.'. Please see InnerException for more details.