Use a utility like WinRAR, 7-Zip, or The Unarchiver. If the file is part of a multi-part archive (indicated by the -3 suffix), you may need the other parts (e.g., -1 , -2 ) in the same folder to extract it successfully.
The .rar extension indicates that this is a compressed archive. It uses the Roshal Archive format to bundle multiple files into a single, smaller package. The prefix task. suggests it was generated by an automated task manager, while l3mtzzcunn-3 serves as a unique GUID (Globally Unique Identifier) to prevent file name collisions. Common Sources task.l3mtzzcunn-3.rar
Continuous Integration (CI) tools often package error logs and screenshots into these formats after a specific test "task" fails. Use a utility like WinRAR, 7-Zip, or The Unarchiver