sorry to hear. We did have a small problem with the last release (which is already fixed) but I think it didn’t really concern bb.nii
Just to be sure, I just downloaded the web-version of Lead-DBS myself and found the file bb.nii correctly within the /templates directory. Did you perchance get Lead-DBS completely from github? Because if so, we don’t have all the large datafiles in the git repository. Github is great to get fast bugfixes and updates but you need to once download the whole repository here from the website.
Could you please retry and download Lead-DBS and check yourself whether bb.nii lies within the /templates directory? Then go ahead and replace your old version of it, make sure, it is on the Matlab path and retry?
Please tell us if there are more issues.