After I made our puppetmasters environment-aware (https://gerrit.wikimedia.org/r/#/c/393677/) the puppet tab stopped loading because the puppet REST api couldn't find the 'puppet' environment.
I fixed this with https://gerrit.wikimedia.org/r/#/c/393819/ but now none of the filter tags are getting loaded -- apparently with environments the code comments aren't provided.
This needs fixing, but maybe can wait until after the 4.x upgrade since everything will no doubt break or change again as soon as we switch over.