I've been fighting with photoscan for a couple hours now. I have all of my cameras loaded into my workspace and when I go to tools>import>masks and select all cameras, have {filename}_mask.jpg, and select my folder, it gives me a "Can't load image:" error. I suspect that it has something to do with a backslash where there is a forward slash in the file naming.
The only thing that seems to work is if I import one single image at a time for one single selected camera. All of my files are named exactly the same with the masks following the {filename}_mask.jpg suffix.
I think this is a bug. But I'm also new to the software.