What does the VIAVI TestCenter validation error "Invalid command input property - handle(3678)" mean?

What does the VIAVI TestCenter validation error "Invalid command input property - handle(3678)" mean?

Back to VIAVI TestCenter error message index  A 2544 test was being run using stream blocks bound to the PPPoE hosts in the simplified test topology below. When the 2544 command sequence was run, the "Invalid command input property - handle" error was thrown. So the "Invalid command input property - handle" means that the stream blocks' configurations had gotten corrupted.  Rebuilding the stream blocks was necessary to clear the error.