Suddenly, I'm unable to edit my photos from Lightroom 5.6 in Photoshop CS6. I have recently converted from Mavericks to Yosemite OS. But, I haven't had any issues for the past week or two. Now, whenever I try to Edit photos from Lightroom 5.6 in Photoshop CS6, either nothing happens. Or from the drop down menu, the option to Edit in Photoshop CS6 is greyed out. Both Lightroom and Photoshop are the latest versions. I've even uninstalled, and reinstalled Photoshop CS6 without any improvement. Help!!!