OK, I looked at the file default.rule file. And I found out that it belongs to the package tracker. However, that package is in universe now. I did not have it installed.
Anyway, after installing the package tracker, nautilus did start. But the thumbnailer still did not work. It did show of course the thumbnails that were created by the official nautilus version, but it did not create any new ones (tiff). So I deleted this experimental nautilus and tracker and returned back to the official ones. ** Summary changed: - Nautilus in Gnome3 Staging PPA will not start + Nautilus in Gnome3 Staging PPA does not create thumbnails (tiff) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1791991 Title: Nautilus in Gnome3 Staging PPA does not create thumbnails (tiff) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nautilus/+bug/1791991/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs