Sudden Error "This file already exists at target location" when saving existing files, creates new -01 file

This just started yesterday when I save SVG files: I get an error message saying that this file already exists at the target location, so it creates a new file with the same name, ending in -01. Whenever I edit any existing SVG file, whether in a desktop folder, iCloud, or in dropbox, it saves the edits as a new file. 

I have uninstalled and reinstalled Illustrator. I have updated my mac software and restarted my computer. Nothing is working to stop this duplication from happening. I just want to save my edits without creating duplicate files! This does not happen when I save them as .ai files, but I use SVG files with a machine that doesn’t read .ai file.