Hi Juan! I have 2 possibles. One I've reported in the past, something you hadn't been able to replicate, but which occurs on my system, a growing number of Windows-based friends, and now a client I tutored on their Mac. When a R-T preview is engaged (circle is red), toggling it off, then ON within the process module causes a momentary white flash- rather blinding. Toggling off, then on in the R-T preview window works fine.
Second, on occasion, I've used SampleFormatConversion to crunch a mask to 8-bit for storage savings. Many masks reduce in dimensions rather than reduce in bit-depth. It seems inconsistent though. Today, one star mask truncated fine, while the other went from 4,656 pixels wide to 1056. Some of Rick's ColorMask's do this, some don't.
Thanks Maestro!