Check that the "infant*.HEAD" datasets are in your AFNI binary directory because they are included in AFNI's default distribution (we may stop doing that in the future to save space and download time for others). The CustomAtlases.niml filename is case sensitive, so be sure it is in that ~/UNC_Infant_Atlases directory. Use "whereami -show_atlases" to see if the niml file is being read properly.