Gatkeeper prevents Photos from importing Aperture Libary I am trying to open a 160GB Aperture Library with the Photos.app
The library can be opend with aperture w/o problems.
As soon as I start opening it with Photos, Gatekeeper starts checking the files.
This seems to take very long. I did let it running for a couple of hours and quit everything.

I tried to disable Gatekeeper with

sudo spctl --master-disable


But that didn't change a thing.
It still opens the dialog and start checking the files, with no progress:
The library was on an external diksdrive.
I set the "Ignore Permissions" option with Command-I for that drive.
Restartet the Mac and opened the library with Photos and the import was done in several minutes.