I found two bugs on the brain mask extraction utility (Diffusion Brain Masking) from diffusion images.
It creates a mask which is just a plain square. I think it is the problem with the option ‘Remove islands in Brain Mask’
If I disable this option, then inverted mask generated.
Please, find images attached.
Stable release 4.10 works fine.
OS: Ubuntu 18.04.2 LTS