Where do you save your files? Network? Synchronized folder?
Which is the exact error message?
What's in the file?
Do you use font management?
Which is the exact file format?
Exactly how do you open that file?
Do all the corrupt files have something in common?
Is a printer connected and turned on?
In the documents of my computer
"This file is damaged and could not be repaired"
Just drawings using the pen tool
Selecting open from the pull down file menu on the top
They all involve a picture, usually one taken from my phone.
I don't have a printer
Please try and set up a PDF printer.
I don't have one. How will that help?
Illustrator writes information about the printer into the file. If it doesn't find a printer when opening the file, things might go wrong. This might be the reason for your issues. But there's no guarantee that it helps.