Hi Guillaume,
is there a problem with just one part of your images? Can you try keep empty information about focal length?
Have you changed the alignment settings? Can you please check if some of the images are not corrupted? IS it possible to process the cameras separately?
Please try to clear the cache, reinstall RC (you can launch RC with holding shift key and choose Make it like a clean install) and try again.
Are you using control points and how many of those do you have? Did RC crash, or only an error showed up?
Where are your images saved? Is this the same when you will use RealityCapture to create JPGs?