Sagenotebook is not evaluating the cell?
sage -n is what I did. I installed sagemath and sage-notebook via pacman on archlinux. I asked them they said it's an upstream issue. However the console works, but I like cells and notebook. Don't use the console.
I waited hours but no response.
Your log you link to doesn't seem to indicate anything disastrous, though Sage 8.0 should deal with the deprecations you see (I think). This would seem likely. It's possible that there is some mismatch between the version you downloaded and your installation machine.