I have both Photoshop CC and Photoshop CC 2014 on my MacBook Pro.
When sending images from Lightroom for merge ring to panorama and CC 2014 is open, the final product is different from what happens in the CC version. The final pano is severely darker on one side and somewhat too light on the opposite side of the panorama.
I should mention that I used Lightroom to color corrected the images used. I used RAW images from my Canon Rebel xTi and all the images are equally lit (or close to it.)
If Photoshop CC is open, and I send the images to merge to Panorama from Lightroom, the final pano is fine and consistent in lighting across the panorama.