On iMac with Yosemite, my screensaver has lost the option to use photos. Where there should be an option to select a photos folder there is only a bar "Screen Saver Options" i.e. color, speed etc of the cg saver options which are still available. If I try to select a photo option e.g. "Photo Mobile" I get an endless rotating color disk.
I have tried reinstalling Yosemite, deleting all screensaver-related plists in preferences and rebuilding iPhoto, with no luck.