Hi Matt,
That's odd, because the versions it should be asking for are Externals-client-v6r6p3-Linux_x86_64_glibc-2.12-python27.tar.gz and DIRAC-lcg-v13r0-Linux_x86_64_glibc-2.12-python27.tar.gz on SL6 variants and *glibc-2.17* on SL7. If you are not on eitehr SL6 or Sl7 it will probably not work, as it's not maintained for anything else.
Before I go and try and hunt down what's going on, could you please try it (from a clean shell) with the version we (as the maintainers) currently recommend[*], which are: