Editing in Photos

I have an M1 Air with a 1 TB internal drive, and this "circle filling" cleared up for me when I dumped about 300 GB from my hard drive. Apparently some of the picture editing involves a bunch of memory swapping to the drive, and there needs to be a good bit of free space. I was surprised that 100 GB free was was not enough. They say 15% free space is the minimum.

If that's not it, then tell us more-- Are you using iCloud to synchronize your Photos? Do you have "Optimize Storage" checked in the iCloud section of Photos Settings? Is you library on an external drive?

Have you tried these things? They're the first things to try:

• Restart the computer (of course, you've done this)
• Use another library if you have one, or make a small test Library with a few pictures in it and see if the same thing happens.
• Make a new user and see if the same problem recurs with it
• Rebuild your Photos Library--close Photos and re-launch by option-command-clicking the app icon. If you use iCloud, this may confuse the syncing for a while.
• Re-start in Safe Mode. This bypasses certain potentially disruptive processes. Safe Mode is different for different computers, so see this:

            Start up your Mac in safe mode - Apple Support 

The idea is to find out if the problem is with the Library, with your account, or with caches and login items, and stuff like that. One of these steps may fix the problem, but their failure to work is also diagnostic.

If you need additional space on your boot drive open your library's package (Control (right) - click on the library and select s\Show Package Contents) and check to see how large the iPod Photo Cache folder is.

If you do a lot of syncing from your iMac to the iPhone it can be become large. Some users have found a GB or more in it. It it's large just delete the contents of the folder.