Usually the error messages of penrose contain exception messages. The exception messages usually very long and contain a lot of technical details like classes and function names of Penrose code. Customer may reads this errors and would not understand the meaning of the errors.
Adding user friendly messages in every possible error cases requires a lot of effort. We need a list of error cases that we support and the appropriate error message for each of it.
The code has been fixed to handle certain types of exceptions in a better way. See: https://bugzilla.redhat.com/show_bug.cgi?id=491140