dowloading a theme is ok at home. 

At my office (French National Education), the themeroller web app works great but the download button does not react, download does not start. Some domains are blocked by our administrator, for example we don't have access to github or mdn. 

So, my question is: are themes downloaded from github? If not, from which domain? Which domains do I need to authorize to be able to download my themes?

Thank you.