afni.nimh.nih.gov

This is strange. The names of the atlases are not the names of the atlas dataset files. They are defined by a specific file. Do you have a file named AFNI_atlas_spaces.niml in your AFNI binary directory? If AFNI_PLUGIN_PATH or AFNI_PLUGINPATH is set, then that directory will control where to look for that file. Otherwise, afni searches the current path for that file. What happens if you type:

whereami -show_atlases