Edit on 2017-06-26: Blender is now on Flathub and this article is now obsolete.

If you're one of the three people using my Flatpak builds of Blender, I'd like you to run the following commands:

$ flatpak --user install bochecha org.blender.app stable
$ flatpak --user make-current org.blender.app stable
$ flatpak --user uninstall org.blender.app master

The reason is that I had made the mistake of publishing the Flatpak build on the master branch, even though it corresponds to the stable Blender release.

I added a stable branch now, and the commands above will move you to it.

For now, the very same Blender release is still on the master branch as before, but eventually I might start pushing nightly builds to the master branch, so you probably want to stay safe and keep using the stable release.