If you are having problems, launching or stability issues then the first thing to try is resetting the preferences of the application. 

This process will reset ALL preferences in the application

To restore preferences quickly using a keyboard shortcut

  • Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (macOS) as you start Illustrator. You are prompted to delete the current settings. The new preferences files are created the next time you start Illustrator.