Can't upload photos: "because you don't have permission to view it"??

[Per Hansa]

MacOS High Sierra 10.13.6. It's been a rough week with my tech. Had an external HD go bad--after taking advice from this forum, I've sent it to a data-recovery company. Yesterday, after discovering I had copied 3 years worth of photos/videos to a separate hard drive, I attempted to drag those files into my "Photos" app. Of the 6,000 files, half of them would not upload to Photos, with the message..."file couldn't be opened because you don't have permission to view it". Opening them using "Preview" works fine, it's just when I try dragging them to my Photos app.
A bit more info on the files:
1) They were previously uploaded to a separate Photos library. About a year ago I copied them from that library to a folder on a separate hard drive. Now that the original hard drive (photos library) is unaccessible, I tried dragging those 6,000 photos from the folder into a new Photos library.
2) After researching solutions from previous threads, I've already tried changing permissions of the folder to "Read/Write", and I've tried moving the problem files to a folder on my Macbook's main HD and then to the Photo library (not sure why that would work, but a previous poster said it had). I also copied the entire folder to a separate external HD and tried uploading from there.
3) Again, it doesn't appear to be a file corruption issue (as they open fine in Preview). Also, all the photos are my own (from my DSLR and iPhone), and they worked just fine previously in a separate Photos library. Perplexed. This hasn't been my week!

Thanks!

 

[Fishrrman]

OP wrote:
I attempted to drag those files into my "Photos" app. Of the 6,000 files, half of them would not upload to Photos, with the message..."file couldn't be opened because you don't have permission to view it".

Did I post to you about this once before?

Try this. This takes only seconds and it may solve your problem.
1. Mount the external drive that has the pics on the desktop
2. Click on the drive icon ONE TIME to select it.
3. Bring up the "get info" box (type command-i)
4. At the bottom of get info, click the lock and enter your administrative password
5. Put a checkmark in "ignore ownership on this volume" (sharing and permissions)
6. Close get info.

Try accessing the pics now.
Any different?

WHAT YOU JUST DID:
By ignoring ownership, anything you copy/open from the external drive now "comes under the ownership" of the account you're using...

 

[Per Hansa]

OP wrote:
I attempted to drag those files into my "Photos" app. Of the 6,000 files, half of them would not upload to Photos, with the message..."file couldn't be opened because you don't have permission to view it".

Did I post to you about this once before?

Try this. This takes only seconds and it may solve your problem.
1. Mount the external drive that has the pics on the desktop
2. Click on the drive icon ONE TIME to select it.
3. Bring up the "get info" box (type command-i)
4. At the bottom of get info, click the lock and enter your administrative password
5. Put a checkmark in "ignore ownership on this volume" (sharing and permissions)
6. Close get info.

Try accessing the pics now.
Any different?

WHAT YOU JUST DID:
By ignoring ownership, anything you copy/open from the external drive now "comes under the ownership" of the account you're using...

Thanks Fishrrman. I checked, but that setting was already checked.

 

[Per Hansa]

For those who may discover this thread in the future while trying to resolve a similar problem, I found a solution...sort of. I still have no idea why I continued having this issue, but as a result of fiddling with it in so many ways, I stumbled across a solution.
The first thing I did was to change the permissions of the drive to ensure it was "Read & Write", and that the "ignore ownership" box that Fishrrman describes above was checked. I then would go back into the folder, "select all", drag into my Photos library, and would continue to get the same message for the 3,000+ remaining photos that would fail to upload (side note, during each attempt I would get the "duplicate photo" message, asking me if I wanted to "import" or "don't import" the duplicates--neither option made a difference, as it would still fail to import the 3,000+ that had yet to be uploaded). Immediately after, I picked just one of the photos it failed to upload, and had the same result--failed to upload because I didn't have permission to view.
I then quit the Photos app, ejected my hard drive, immediately plugged it back in, launched the Photos app, and once again tried to upload just one of the problem photos--this time it worked! I tried one additional photo, worked again. So I clicked "select all", drag and drop, "don't import duplicates"....and got the fail message again for 3,000+ photos. So I shut everything down again, relaunched, and this time would highlight 10 at a time (worked), then the next 100 (worked), then the remaining 2,500+ (worked). As long as I wasn't including the entire folder (those which had already imported), it worked ok. And for whatever reason it was chronological, which I hadn't noticed earlier--it was the first few thousand photos in the folder that had downloaded successfully initially, and the bottom half of the photos within the folder that I needed to select separately in order for them to successfully download.

I've got them all now, but I'm still curious as to what may have caused this glitch.