I recently upgraded Lightroom 5 to Lightroom CC and downloaded it according to the explicit instructions, as well as updating my video card. What started as an intermittent problem now occurs all the time when I try to edit a photo in LR CC 'Develop' or edit in Photoshop CC. The program immediately freezes ('not responding') , even if I restart the computer. The previous LR5 always worked seamlessly.
I use a PC running on Windows 8.1 64bit.