Value of type '|1' cannot be converted to '|2'. Type mismatch could be due to mixing a file reference to '|3' in project ...

Value of type '|1' cannot be converted to '|2'. Type mismatch could be due to mixing a file reference to '|3' in project '|4' with a file reference to '|5' in project '|6'. If both assemblies are identical, try replacing these references so both references are from the same location.