Digital Light & Color

Try this:

Color Remap
Shift key | probe a point
Open Edit ending color
Remove color pair
Shift key | probe another point --- fails

I can provide K. and J. one of the image files that failed if needed

Try re-activating the transform's Probe by clicking on it, then shift-left-click an image color or colors for the next color pair or pairs...

...den...

Yes, den. Not a code bug. Good.

Still, the dialog opens with the probe button activated. The behavior seems inconsistent within the dialog, as I reported, and also don't most dialogs open with the probe button if any not activated?

I modified the code to automatically re-activate the probe in the transformation window when you delete a color pair.