Can't open existing files in Illustrator

I had a problem years ago that was fixed by changing user. There was a character in the username that was causing a problem. I hope changing username works for you.

Otherwise, what I was going to suggest was to try try opening the Illustrator file in Acrobat and from there open it in Illustrator.

Hi @alexe16919786,

Thanks so much for reaching out and sharing the screenshot. I can imagine how frustrating this must be, especially when you're working on tight deadlines.

Since the file opens fine on another machine and user account, it seems the issue might be related to your current system environment or user settings rather than the file itself. Could you please confirm your exact macOS or Windows version along with the Illustrator version you're using?

It would also help to know if this happens only with this particular file or with other files too.

I'd recommend testing the file in a new local user account on your machine to see if the issue persists. You can also try starting your system in Safe Mode and then opening the file. Here are some references to help you with that:

Set up a new user on Mac: https://adobe.ly/4eUJlsL

Set up a new user on Windows: https://adobe.ly/46IKf9w

Please keep me posted on what you find.

Looking forward to your update.

Abhishek 

Was the Illustator file created by Illustrator or could it have been exported in .AI format by another application?

I'm currently seeing bad issues with .AI files exported by CorelDRAW; if the files contain any live text objects Illustrator will refuse to open the file. This is solved by either opening the file in an older version of Illustrator (such as version 28) and then re-saving the file there or by converting the live text objects to outlines in the application that exported the .AI file.