Aperture doesn't start after installing OS X Yosemite
Hello,
these days I made a new installation of OS X Yosemite using an USB stick. Everything's fine so far except Aperture. I purchased Aperture in the Mac App Store an installed it from there. When starting Aperture I get an error message saying Aperture cannot be opened because of a problem. I deleted Aperture and installed it again from the Mac App Store but still the same error.
Any ideas what's wrong? How do I get Aperture working?
When upgrading to Yosemite from Mavericks everything was fine and Aperture was working. Only with the fresh Yosemite installation there seems to be the problem.
iMac, OS X Yosemite (10.10)