The CndValidator does not stop validating once an error is found. It is quite possible that validation will find more than one error. The CndValidator tests are checking to make sure the ValidationStatus is an error when an error is expected. However it does not check that the specific error is the one that is expected. So it is quite possible that a test could have a "false positive" result. There needs to be a way to make sure the expected error is contained in the ValidationStatus object. Having a code attached to each status message would be one way to do that. The test could then check to make sure the ValidationStatus contains the expected code. It also might be a good idea to move the validation messages out of CndMessages and iron their own properties file.