Several times after our app pool has been told to reset, it gets stuck, the .net pages go down and the following error appears in the application event log: Failed to execute request because the App-Domain could not be created. Error: 0x80070057 The parameter is incorrect. Our app pool is scheduled to automatically reset at 4am, so the errors stay up until we manually restart the app pool. Has anyone else encountered the error or know of any solutions? Research has suggested it's a permissions issue, but the permissions don't change and the error happens infrequently. The site has no other permission based problems and the app pool identity has permission where needed.