Which step asked you to localize these points exactly?
Could you copy-paste here the message you get?
However after doing Overlapping spehere > Check spheres, this image is what I get.
I pushed a fix to this bug: Bugfix: Volume scout menus incompatible with OS spheres display · brainstorm-tools/brainstorm3@bc6c137 · GitHub
Please update Brainstorm and try again.