Zero active kernels on jupyter notebook



I am trying to run the jupyter notebook from cloud9. I followed the discussion in this thread and at first it seemed fine, I could start the notebook without big problems.

However, when I start working on it and open an existing ipynb file and try to run a cell nothing happens, and a “not found”/404 error is returned. The same happens if I try to create a new notebook: a “not-found” pop-up error message is returned.

(Not sure if related to this but it also seems that existing notebooks are labeled as “not trusted” which I’m not sure what it means).

Anyway, the problem really seems to boil down to no kernel being found. In the terminal I can in fact notice:

[I 23:49:40.154 NotebookApp] 0 active kernels

Has anyone experienced this problem or has an idea about how to solve it? Thank you.