Illustrator 26.5 and 27 won’t open on Mac

Hi @gcappuccia, 

Sorry about this experience. I would like to know if the steps suggested by @Bill Silbert helped to resolve the issue. If not, please submit the crash report by following the steps shared here: https://helpx.adobe.com/in/illustrator/kb/crash-next-steps.html  and restart your machine and check again.

While submitting the crash report, please use the same email address with which you are signed in on this community. This will help us find the crash report and help accordingly. 

Regards,

Srishti

Try resetting your Illustrator preferences. This will restore the program to its defaults which hopefully will fix the issue.

To do so on a Mac:

The User Library folder in which InDesign’s preferences are stored is hidden by default on most Macintoshes. To access it make sure that InDesign is closed and click on the desktop to launch a Finder Window (Command-N). With this window in column view follow the path User>Home folder (it’s the folder with an icon that looks like a house—it may have the user’s name rather than “Home”) and click on the Home folder. With the Option Key pressed choose Library from the Finder Go Menu. “Library” will now appear within the Home folder. Within the Library folder find the folder called Preferences and within it find the folder called “Adobe InDesign” and the file called “com.adobe.InDesign.plist” and delete both that folder and that file. When InDesign is next launched it will create new preference files and the program will be restored to its defaults. 

The advantage of manually deleting preference files in this manner is that after you’ve reset up the program (make sure that no document window is open) to your liking, you can create copies of your personalized “mint” preference files (make sure that you quit the program before copying them—that finalizes your customization) and use them in the future to replace any corrupt versions you may need to delete.