I’ve been in the process of finding & switching to an Aperture replacement.  I had carefully declined to use Photos so as not to confuse things - but I think at one point I clicked something unintentionally, because all my Aperture photos became available in Photos. 

A few key books I’d made in Aperture got lost in the process. 

Moreover, despite trying to disable Photos and reactivate Aperture, none of my Aperture Projects populate with their photos, though all of the photos are visible in Aperture’s Photos view. 

Another anomaly:  occasionally the photos do start showing up in the respective Projects but wink back to blanks after a few seconds. 

Every time I open or close Aperture, I get the message about needing to repair the library.  I have tried that repeatedly, but it always hangs up at 96% and I finally resort to force quit (after hours of waiting).

Any thoughts??