Dave Y

tried to update from lightroom 5.7.1 to lightroom cc2015 always stalls and fails at 42%. using a pc with windows 7 ultimate creative cloud worked fin up until I tried this update. I have also lost lightroom 5.7.1 so no lightroom at all photoshop cc2014 and Bridge still work ok anybody got any ideas as to what the problem could be. I have been on to adobe help desk twice with no resolution