Hello I'm trying the latest Galaxy (git status gives me : # On branch release_16.07) I've set the xsend option in galaxy.ini (in order to run Galaxy behind a web server proxy, and apply all methods described here : https://wiki.galaxyproject.org/Admin/Config/ApacheProxy) apache_xsendfile = True HTML, gff3,tabular files are just fine but the preview of some other files (txt, csv) is broken on the interface. When I want to preview a txt file : Not Found The requested URL /datasets/fd1df6a9052810d5/display/ was not found on this server. And apache says : [Thu Aug 18 15:33:48 2016] [error] [client 192.168.29.12] (13)Permission denied: xsendfile: cannot open file: /softs/bioinfo/galaxy-prod/database/files/000/dataset_19.dat, referer: http: But it looks like this is not really a problem related to access. Indeed, from the same file, I switch it from txt to tabular (edit attributes), the preview works. Are you able to reproduce the behavior ? The same problem occurs on release_16.01. It's fine with the release v15.05 which is my production server right now. Fred