lost Photos library in Mojave
Migrating from the old computer I lost Photos library, but It is in iCloud. How do I transfer the library to my new iMac?
You can do the following:
1 - create a new Photos library.
2 - set it to be the System Photo Library.
3 - enable iCloud Library in its preferences.
4 - do not enable "Optimized Mac storage" unless you don't have enough room to house all of the full sized image files.
5 - wait for Photos to download all of the image files, albums, projects, etc. from iCloud to your library.