The exception I hate the most previous: High performant way for waking REALLY fast next: Code Critique: Transactional File And just for fun, it is reproducable if you run 824 tests, but not if you run a single test! Update: Found the guilty test, and it is one that used to work, damn it! Comments 07/27/2008 02:43 PM by Igor T. Maybe you have kept the state somewhere? 07/27/2008 02:45 PM by Ayende Rahien Do you SEE the exception? 07/27/2008 06:56 PM by Jesse Ezell "Execution engine errors are fatal errors that should never occur. Such errors occur mainly when the execution engine has been corrupted or data is missing. The system can throw this exception at any time. When possible, the system throws an exception that provides more information than the ExecutionEngineException exception." Damn. What did this? 07/27/2008 07:06 PM by Ayende Rahien This usually occurs when you are working with Reflection Emit and managed to get by the Invalid Program Exception Comments have been closed on this topic.