Can't copy photos from backup drive to new iMac

[BrookF]

Hoping someone can help with this one. Our old iMac experienced a white screen of death, and after trying pretty much everything to fix it, we decided to bite the bullet and buy a new iMac. When I tried to use the migration assistant to restore the machine from the external backup, I received an error message that basically said that the function could not be completed because the backup was from a different system/format. I was able to manually copy a good portion of the backup to the new iMac, however, I can't copy the photos. When I try to open the iPhoto library from the backup, I receive an error message that says "Cannot import items: These items cannot be added to your Photo library because the file format is not supported by Photos." Is there any workaround that will allow me to copy all of our old photos from the external backup to the new iMac? Thanks in advance.

 

[PaulD-UK]

Hi I had this error message when trying to copy 50,000+ photos from and old iMac to the new one running Mojave. Trial and error led to me getting the update done by only trying to import about 300-400 at a time - it took hours. Once I tried selecting too many the error kicked in. There was nothing wrong with the format of the old photos, which were mostly iPhone camera originals.
However the library had been converted from iPhoto to Photos on the old iMac (late-2009 running El Capitan).

 

[BrookF]

Thanks. Unfortunately, I did not convert my library over from iPhoto to Photos like you did, so I'm stuck trying to convert the original iPhoto library from my external backup. There is an iPhoto Library Upgrader tool available that I downloaded, but it doesn't seem to be recognizing the library (it's grayed out when I try to select the library in the tool).

 

[Fishrrman]

Something you might try:

1. Copy the old iPhoto library from the external drive to the internal one (assuming there's room to do so).
2. Now, "re-import" the library if possible (instead of trying to "convert" the existing library).

Might work, maybe not... might be worth the try.