[galaxy-dev] Unable to add tools from tool shed

I'm following the guide on https://wiki.galaxyproject.org/Admin/Tools/AddToolFromToolShedTutorial to add a tool from the tool shed. The tutorial uses 'bwa_base', but I don't see that. So instead, I'm using 'bwa_mem'. I choose 'Preview and Install', then 'Install to Galaxy'. I then select to have it installed in 'NGS: Mapping' tool panel, then click Install. The page then shows two tools: bwa_mem, and package_bwa_0_7_7. Both of which show 'Error' as the status. Clicking on 'bwa_mem' shows some information with "This repository is not installed correctly (see the Repository Installation Error below)...." What does this mean? And how do I fix it?