404 for organisation repo that contains plain html

Hi guys!
Our repo contains the plain html sources (built by travis from the documents repo) of the page to be published on xmpp-grid-broker.github.io on the master branch. Opening https://xmpp-grid-broker.github.io/, however, results in a 404.
In the settings under “GitHub Pages” it correctly states “Your GitHub Pages site is currently being built from the master branch”. No errors or further hints are displayed. We did also not receive an email reporting an issue.

Is there any way to get more details that could help us to investigate this problem?

Thanks!
Raphi

the good old "Have You Tried Turning It Off And On Again?"did the trick. I had to delete the master branch and create it agan…