Photos Export Errors

This excellent article by Leonie will help you weed out legacy media - lets hope this is part of the problem and not missing photos.

https://discussions.apple.com/docs/DOC-250002727

There is a thumbs folder in the resources/derivates but I don't know if it can be read. Perhaps one of the more technically capable contributors may be able to advise.

You mention that the slideshow works for these photos, can you create and save one of these slideshows? Its a last ditch attempt but at least it could be one way of saving the photos even if they can't be edited and separate exported. The other, very desperate attempt for your memorable photos would be to view them on screen and take a screenshot of them (shift-cmd 4), as this would be create an individual file for the photo. The quality may not be great, but better than losing them altogether............

I'm afraid it is likely that when you set optimise storage the full resolution file was removed from the library and therefore is no longer available unless you have a backup stored somewhere.

Two things could you try. If you download Power Photos, there is a free trial version, you can right click on a photo and it will show you the file path to the photo within Finder. You can at least examine the file directly to see if it is corrupted, assuming it exists. If it doesn't at least you'll definitely know the reason.

Secondly, iCloud Photos only supports certain file types:

https://support.apple.com/en-gb/HT204264

and it may be that some of the photos in your library are older file types and therefore cannot be uploaded. If so, by using Power Photos you'll at least be able to access and copy the file directly and then convert it or store it elsewhere.

Good luck

You're welcome, hopefully we are starting to get some answers. In answer to your questions:

1) The image you are seeing is the thumbnail, so, yes that does exist and if the resolution is good enough you can export this thumbnail and re-imported it as an image file. There was a similar question on another thread earlier this week and Leonie gave a solution - I'll try and find it.

2)I think iCloud would have just ignored it, the rationale probably being that it is not a supported format and therefore shouldn't be there in the first place! But I agree, an error message would be helpful. I think the only way to identify them is to create a smart album with the rule 'Unable to upload to iCloud'. These type of maintenance albums are good to create and check periodically. As an aside about a year ago I noticed that I had lost the edits on over 2,000 photos, they all reverted back to the original image. I've still not been able to work out on how earth it happened. Since then I have a smart album with 'Photo is edited', I check this every so often to make sure the number of edited photos doesn't suddenly change and if it does, I'll have a recent Time Machine backup to recover from. I like the Photos app and is great for managing photos that I take with my phone, but I don't like the way it stores the photos in a single library as strange things can and do happen so its important to understand a little about how it works and to have a few backup strategies in place.