macOS Tahoe 26.2 and 26.3 - Files not Saving

Hey all,

I had this issue in macOS 26.2, do I updated to 26.3 hoping things would improve. Both have issues.

I try saving, the percentage goes up slowly, but eventually goes back down and keeps showing different seemingly random %s. It'll go 15%, then 34%, then 76%, then back down to something like 26%, then 40%, and just keeps going for maybe 10 or 15 minutes. It then eventually gives up and shows the error below:

I've tried:

• Restarting Illustrator (and attempting to save the recovered file)
• Restarting the computer
• Checking for Illustrator updates (it's fully up-to-date)
• Saving to a different location (like the Desktop)

Some information:

• I'm not using any 3rd party plugins.
• Files do save if I create a new one from scratch and try saving it. Existing files do not.