Mac OS X 10.10.1 (yes, Yosemite...)
Lightroom 5.7,1 (CC version)
When trying to import some libraries from aperture I get this immediate response "Failed to obtain image version information from Aperture library".
In the plug-in import window, Number of image/video files is "undetermined", as well as Disk space required.
Tried with different Aperture libraries, but with the same negative result.
The plug-in worked in previous Lightroom version or when it was a stand alone plug-in.