Do you ever have that issue with an Adobe Illustrator file where you try and open it only to get a message saying “an unknown error has occurred”? After a lot of frustrating experiences with evil corruptions like this, I found a fix for Macs to recover the file so it can be opened again. Simply open the Disk Utility and verify and repair the disk permissions on your main drives. Now go double click your file and watch as it obediently opens. Your world makes sense again. You’re welcome. The unknown error in Adobe Illustrator has been tamed.