The other questions were mostly for the Biobakery server (previously the Huttenhower lab). The people who run that server host there own forum for question since the tools are slightly different than those hosted at UseGalaxy.org (how this question was tagged).
The Biobakery forum is linked from that servers homepage. If you can’t find it, or are working somewhere else, which public Galaxy server are you working at? Find the URL at the very top of your browser tab.
Xref: Data import LEfSe error: Cannot count lines in file - #9 by jennaj