When I load a set of Canon CR2 RAW files into Helicon focus for stacking
it errors and says "Adobe RAW produced an error loading this RAW file, do you want to switch to another RAW processor"

this only happens on RAW files that I edited with Canon DPP ; after I say, no, don't change anything, the ...

During Retouching, I have the old picture on top, and the stacked image below
I have (let's say) 10 old pictures
Picture 1 is selected by default as first to compare and use for retouching
I retouche, ready, now I select picture 2
picture two starts loading, I can see on the status bar below that ...