Problem editing photos in MacBook Pro photo library

Photos can show thumbnails, and even screen sized previews, without actually having access to the original file that's needed for editing. It sounds like Photos has lost contact with some (or all?) of the originals files.

Photos is designed to keep the Original files, always untouched, in its Photos Library package. One possibility is that this was defeated at some point in the past. In Photos' Settings>General

the "Copy Items" box should be checked. (This makes a "Managed" Library.) Has yours ever been unchecked? If it was (usually very unlikely making it a "Referenced" Library,) then the Originals were left in Finder folders, and those have been moved so that Photos can't find them, anymore. If you can find them and move them to a convenient spot, then you can use the Photos' menu File>Consolidate to put them back together. You can find Reference files with a Smart Album:

If this isn't it, then Photos has lost contact with the Originals for some other reason. It might help to rebuild your Photos Library--close Photos and re-launch by option-command-clicking the app icon. If you use iCloud Photos, it’s possible that this will cause a re-sync that lasts long enough to make you nervous.

Let us know…

Perhaps not the originals are missing but the edited versions, Richard? The error message "Photos cannot load edits for this image." is typical for a damaged Photos Library, where Photos cannot access the edited versions (wrong file system format, problems with the file ownership, or a damage caused by a cleaning app, that replaced the originals by the edited versions and created a mess, or a problem when trying to access iCloud Photos because of lack of storage).

If a cleaning app should have damaged the library it may not be possible to repair the library, then it would be better to restore the library from theist backup, that has been made before the problem first occurred.

Thanks for the additional tests and insight, Richard. You have been brave to risk your library.

I got this kind of error message, when I tested the trial version of CleanMyMac on a small test library.

It would help to know, if BStuts is using iCloud Photos and how much free storage is available in iCloud and locally on the Mac and where the library is located.

léonie wrote: …I got this kind of error message, when I tested the trial version of CleanMyMac on a small test library.

Good point! It could be "Cleaners" or "Virus hunters" corrupting the Library database.

(Of course, I was only risking a test Referenced Library…not very brave!)

léonie wrote: Perhaps not the originals are missing but the edited versions, Richard?

I guess that's why more than one person reads these!

I don't think that I've seen "Photos cannot load edits for this image" with my Libraries, but I think I've seen "Cannot Start Editing." "Cannot load edits" certainly sounds like a corrupt database. "Cannot Start Editing" sounds like missing originals, or something similar. However, I just tried it with a deleted referenced original, and I got this:

which is different.

I tried giving myself Read Only permission on a picture, and I could edit it. I guess that's because an original is not altered.

Feeling like a criminal, I messed around with "masters" and "derivatives," and I can't create the error. I throw files away, and Photos just recreates them. I didn't fool around with the database, itself.