At least two of the computers in our office are having issues with the latest Illustrator update 25.3.1. The program does not open when selecting a file and performing Open With>Adobe Illustrator 2021. The program does not open from the start menu. The program does not open directly from the Illustrator.exe file. If you try to uninstall Illustrator with Creative Cloud, it tells you that you can't because the program is open. If you go to the Task Manager with less detail, Illustrator does not show open, however, if you select more detail, you may see 14 or more processes for Illustrator currently open. After a lot of investigation by myself and our I.T. Department, we've discovered that if we try to open Illustrator 3 to 4 times it will eventually open but that is a nuisance.