I've been using Illustrator 2020 24.0.1 64-bit and after a while, I can't save an .ai file anymore when I make changes to it, the message appears: "Cannot save the illustration. Maybe the file is read-only or is being used by another application, or you don't have the necessary permissions. Save the document under a different name, in a different folder or directory. Identification: -54 ".
When I try to Save As ... it doesn't save as an .ai file, but as a .tmp file and with the random name "~ ai-3cb4f2a4-769b-4f86-99a2-a05daf604013_".
When I go to Export to screens ... to PNG, the files are saved with the ending .tmp $$. If I rename, remove that ending .tmp $$ and leave only .png, the file looks like a normal image, but that shouldn't happen when I export!
If anyone has been through this or knows how to solve it, please help me!