Unable to export unmodified original (Unknown error -1)

Your screenshots are showing two interesting items. The first screenshot is showing a button "Reveal in Finder". Does this button produce the original you cannot export?

In the second screenshot you have an album "Unable to upload" selected. Is this album empty or does it contain the items you cannot export?

Items in "Unable to upload" are usually items with missing originals, incompatible codecs, or incompatible color sync profiles.

Missing originals can be caused by third-party applications, that try to remove duplicates from the library and are modifying the library directly.

Have you ever used any third-party application to remove duplicates, that could have modified your library? If yes, you would have to recover the missing originals from a backup or our library, from the time before you have used the "cleaning" application.

If you have enough free storage to hold a duplicate of your current Photos Library, there is an easy way to isolate the originals in the library package, if the originals and edited versions are still there. You just have create library, where you have removed all items that can be exported. Then the library folders will only hold the items you are trying to find.

• Duplicate the Photos Library.
• Open the duplicate of the library in Photos.
• Create a new standard album named "unable to upload standard" and drag all photos from Unable to upload to this standard album.
• Now you can create a smart album "Able to upload" (File > New smart album"), set the rule to "Album is not 'unable to upload standard'".
• Now open the new standard album and delete all photos from your copy of the library in your "Albe to upload" smart album. Do it in easy stages, no more than 1000 items at once. And delete them from "Recently Deleted" at once.

Once the "Able to upload" smart album is empty and "Recently Deleted" as well, look at the "originals" folder in the library. select the copy of the library in the Finder, Ctrl-click it, use "Show Package Contents".

Are there any originals left or is the originals folder empty? Or ist there a Masters.legacy folder? Look there as well. If you can isolate the originals, you can test. if they can be processed by Preview. If yes, try to reimport them to your other Photos Library.

Look at the other folders mentioned by Richard. You may have isolated the Previews as well.

One way to go would be to look inside A COPY OF the library package originals folder, and try to find your files. If you remove the ".photoslibrary" suffix, it will behave like a normal folder. The original picture files are in the "originals" folder, holding 16 file folders, 0 through F, and each may have a couple thousand pictures.

The file names are not the original names-- they are unique creations with no order or meaning, like F2D4A6A0-8824-4EA2-8466-E8D19F6BC304.jpg--this was in the F folder. Their original names are kept in the Photos database, but they are not kept in the files' metadata. So you can't search by file name.

PowerPhotos lets you view the pictures in a Photos Library album as a list that can be sorted by date, so you could use that. If you know the dates of your 2700 files, then you could order each of the 16 folders by date, and find them that way.

Or, you could show them in a grid and find them by sight. Either way seems really time consuming!

Again, CAUTION-- only mess with a copy of the Library. All the information is contained in the database, so anything you do that changes what the database expects may make the Library unusable.

I think that's what I've got...

Thanks, Richard. Sometimes I am having a brainwave 😄.

It would still be good to know, why the originals cannot be exported.

For example, we know nothing about the history of the current Photos Library. I have not seen in the discussion, if the library is still stored in the same location, where the videos and images originally have been imported.

We only know, that the file system is APFS, but not if it is case-sensitive or not. A case-sensitive file system format could explain, why some originals could not be found.

The history of the library also could matter. There has been a short time, after the upgrade to iPhoto '11, when Apple made iPhoto and Aperture compatible, where the migration from iPhoto to Aperture imported the iPhoto items as referenced. Quite a few users have been trapped by this, because the originals remained in the old iPhoto Libraries, after the libraries had been migrated to Aperture. And when they then discarded the old iPhoto Libraries, they deleted the referenced originals.

Old Toad brings up an important point-- if you can see the problem pictures in Photos, then those files must be inside the Photos Library package somewhere. In fact, if you order the package contents by size (again--using a COPY of your Library package), you will see that there is a folder called "resources" that is very large, and inside that there are two folders, "renders" and "derivatives" that hold copies of many of the pictures in the Library. Some of these seem to be in full resolution. They are edited versions, not the originals.

When I did a search in the package for a one picture, for instance, I found 4 copies in the package-- the original at 6.4MB, a 110kb thumbnail and a 352kb version in "derivatives," and one in "renders" at 4.5MB

Since these folders have fewer files than "originals," you may be able to sort through them more quickly, and the 2700 pictures that you can see in preview but can't export should be in there, I think.

Taking screenshots, as Old Toad suggests, could be faster, though lower resolution, than sorting thought crazy file names. You'd have to try it to see how it goes.

Is it a photo you can do without? If it is just delete it and continue with the exportation.

the -1 error code means the original image file is missing from the library leaving only the preview file.

If you need the photo you can open the preview version by double clicking on the thumbnail and take a screenshot of it. Then delete the preview as you would any photo in the library.

It can be done as I described as I did just that with a text library.

léonie said:

You just have create library, where you have removed all items that can be exported. Then the library folders will only hold the items you are trying to find.

That's so simple and obvious, now that you tell us !