Ardour crash

Hi. I’m testing right now Ardour 4rc3 and I have a problem. Everytime Ardour start scanning my plugins the Maschine freeze the program so I have to force quit it.The same happened with rc1 and rc2. Maybe the bug was there even in 3.5?
My system:

MacOS 10.9.5
2009 dual-core iMac
8gb ram