Photos disappear in Photos.

[cheddar-caveman]

Cannot find any specific place to post this so it's here.
2018 15" MBP running Mojave 10.14.6
I do all my photo processing in Photos so frequently "export" (copy) an image to my desktop for inclusion in forums and the like.
Once I have used the image I move it to trash so my desktop doesn't become too cluttered.
However, recently, if I have moved the photo from the desktop to trash, when I go back to the original in Photos I get the following error message:

As far as I'm concerned the "original" is the one residing in Photos, not the one I copied over to the Desktop. If I then "put back" the photo from the trash, everything is OK.

This has only recently started so what could have changed to cause this very annoying happening?

 

[ApfelKuchen]

I think this may be a matter of how you import photos into Photos.

Check this setting: Photos > Preferences > General > Importing: Copy items to the Photos library.

If it is not selected/checked this particular dialog box is more likely to appear.

The filename is clearly a photo from a "regular" camera (not iPhone/iPad). How do you Import those photos into Photos? Do you connect the camera or SD card to the Mac and use Photos to Import, or do you use another method, like Image Capture and saving the images to a folder structure of your own design? If the original Import did not copy the image into the Photos library and then the original was moved/deleted, you'd see this dialog box.

There's another possible scenario - that after you Exported the edited image to Desktop, you then Imported the edited version back into Photos. If you did that and Copy items to the Photos library is not checked, and you trashed the edited version from the Desktop and you then tried to open the edited version in Photos rather than the original image... You'd get that particular result.

For what it's worth, I also Export to Desktop when I have an image destined for publication on a forum like this one. One difference is that I have a folder on the Desktop dedicated to that task - "For Upload." It keeps things less cluttered, and the purpose of the folder is clear (well, clear to me). There will be times that I Airdrop images to my Mac and then Import to Photos. "For Upload" helps ensure that I won't accidentally re-import those images into Photos. (And I do have a check-mark in Copy items to the Photos library.)

 

[cheddar-caveman]

I think this may be a matter of how you import photos into Photos.

Check this setting: Photos > Preferences > General > Importing: Copy items to the Photos library.

If it is not selected/checked this particular dialog box is more likely to appear.

The filename is clearly a photo from a "regular" camera (not iPhone/iPad). How do you Import those photos into Photos? Do you connect the camera or SD card to the Mac and use Photos to Import, or do you use another method, like Image Capture and saving the images to a folder structure of your own design? If the original Import did not copy the image into the Photos library and then the original was moved/deleted, you'd see this dialog box.

There's another possible scenario - that after you Exported the edited image to Desktop, you then Imported the edited version back into Photos. If you did that and Copy items to the Photos library is not checked, and you trashed the edited version from the Desktop and you then tried to open the edited version in Photos rather than the original image... You'd get that particular result.

For what it's worth, I also Export to Desktop when I have an image destined for publication on a forum like this one. One difference is that I have a folder on the Desktop dedicated to that task - "For Upload." It keeps things less cluttered, and the purpose of the folder is clear (well, clear to me). There will be times that I Airdrop images to my Mac and then Import to Photos. "For Upload" helps ensure that I won't accidentally re-import those images into Photos. (And I do have a check-mark in Copy items to the Photos library.)

Many thanks for that very helpful reply. No I didn't have that "copy to the library" on, it is now!
Yes the photos are directly from my camera, I plug the SD card directly into my MBP.
Having made that change to the import flow I'll see if it solves the problem.
Many thanks