We are investigating. Reducing the size of the window is most likely to help at this point, as the challenge here is the number of pixels being served up on the 5K screen.

Wait - let me explain what we found first as this may help others.   The pattern you need to be most careful of in using Lightroom: lots and lots of brushing or spot heals are what typically cause…

For those of you still having problems with this, can you confirm you've tried Scott V's Solution 2: Set permission to SLStore & SLCache Folder...

Hi Sebastiaan,   If I contact you offline, would you be willing to share one of these photos with me so we can check it out?   Julie

Thanks for calling that out, Maksim. I've got some further questions out to our support people on that change.

The yellow bar is actually a highlight intended to draw attention to the filmstrip from one of our help tips in the Develop module. We don't understand why it's appearing when that tip is not…