Photos can't find original file location

The files are still located on my computer as none have been moved and I can find them when using find any file, it's just that there are over 6,000 files that are "unable to upload" so it would be quite onerous to do one by one.

Are the files that cannot be found inside the Photos library in the Masters folder or referenced by Photos in a folder outside the library?

If the photos are in a folder outside your library, check where Photos is expecting them to be. The error message you get, when you try to edit or export the original file should show you the file path to the folder, where the photo should be. Where is that? Try "File >Show referenced file in Finder". It will open the folder where the original should be. Where is that?

hmmm, i simply get error message 1,019 could not load image.

This usually happens, when Photos has lost to the connection to Photos it should be able to find in its own Masters folder in the library.

Where did "Find Any File" find one of the missing Photos?

Could you post a screenshot? we need to know the path to the file where the missing photos actually are.

And where is your Photos library stored? Is it in your Pictures folder or on an external drive? Did you run any cleaning software on your library to remove duplicates or similar?

And what version of Photos and of the OS do you have?

The locations where you found the photos do not look good. None of them has the original master files.

• The first location is the Thumbnails folder rin your old iPhoto Library. It has only smaller versions of your photos.
• The second folder has the thumbnails in Photos Library. the best quality is the 1024.jpg version, with a maximum pixel size of 1024 pixels in the longest dimension. The photos should be in the folder Masters, not only Thumbnails.
• Only the last location Library > Application Support > iLifeAssetManagement has the full version of your photos. That is, where the photo stream is buffered on your Mac. It will have the last month's worth of photos.

If you open the folder ~/Library/Application Support/iLifeAssetManagement/assets/sub from FindAnyFile, you can copy the remaining high quality originals out and reimport them. It is not possible to reconnect them, because Photos treats them as managed photos.

It is misterious how the originals may have managed from your photos libraries. Have you been running any cleaning applications like CleanMyMac to remove duplicates?

YYes, try the Time Machine restore. Make a copy of your current library on an external drive, so you can restore the newer photos from that library.