I’m persistently getting an error from ViewPoint within PhotoLab, making the same sort of adjustments I’ve made many times before with no issues. I’m running the latest version of PhotoLab Elite (7.4.0.151) and, after first encountering the error I’m about to describe, I updated to the latest version of ViewPoint (4.14, from 4.12). I’m processing a Canon S110 raw file of a cityscape, and I went to square it up. After setting the horizon to 0.25, I went to adjust Perspective Up/Down. Regardless of whether I type a number or slide the slider, it immediately replaces the image with a gray screen featuring the error message, “Internal error (Failed to normalize or project estimated keystoning lines)”. I can Edit → Undo to recover, but trying again produces the same error. On the other hand, merely returning the control position to 0 leave the error up.
Here’s a crop of a screen-capture of the error message, FWIW:
Does it work if you try the same in the VP standalone program?
Anyway, you should submit the problem to the support.