When I open Photos I get an error message saying "Photos cannot find the System Photo Library named 'Photos Library.photoslibrary'"
IMy computer was hd acned I brought it into local Apple store where they deleted the rogue software and then removed all of my applications etc and copied it to a external hard drive. I then loaded the apps etc back on the cleaned iMac but since h'act been able to open my photos and get a message that some of my data is not being backed up. Any suggestions?
[Re-Titled by Moderator]