Actually all import attempts fail. Even from an SD drive.
Repair fails with the message "Library repair failed".
Also, tried editing an existing photo that was imported under Mojave and got this error message: "Error Downloading Photo - An error occurred while downloading a larger version of this photo for editing. Please try again later"
I'm using a MacBook Air (13" early 2015) running Catalina 10.15.2 and the photos library is on a Mac G5 running OSX 10.5.8. Of course this setup has been working just fine up until installing Catalina.
Also, Image Capture cannot read the SD card while the finder can read it just fine. Nor can it read another camera (Lumix LX-100 in PTP or PC direct modes).
However, Image Capture was able to read and copy iPhone photos to my Pictures folder
How can Apple release such broken software like this?! It's quite appalling.