Opening photo library from an old iMac

Hi, I am attempting the same migration. The photos seem to have migrated, but I cannot view. An error message is presented when I attempt to view:

Error Downloading Photo

An error occurred while loading a higher quality version of this photo. Please try again later.

I tried again later and received the same message. I can access the existing pictures in Photos. I cannot view the migrated pictures. However, the videos migrated and can be viewed just fine. Is there something else I can do to access the pictures here?

What is the filename of the library?

The library you are moving is one that has already been updated for a later version of MacOS on the old machine.

You need to find the library is was updated into.

How did you migrate the library?

How are you changing between "exisiting pictures" and "migrated pictures"

Are you using iCloud photos?