HL-5240 FAQs & Troubleshooting HL-5240 Not your product? Sort by: Updated Date Popularity 2 Results 1. 04/20/2022 The message "[file name] can't be opened because it is from an unidentified developer." appears on OS X v10.8.x. 2. 11/19/2014 The error message "Invalid format for short nick name" appears when printing a document. (Mac OS X 10.5 or greater) Error Messages FAQs & Troubleshooting