500 Internal Server Error with Jupyter Notebook

Hey, I set up paperspace using the fast.ai template but when I tried opening the lesson1 jupyter notebook and some other jupyter notebooks it gave me an error. The error said ‘500: Internal Server Error’ in big red letters instead of showing the coding cells. PLease Help

That’s not the actual problem. The cause is, “No module named jupyter_contrib_nbextensions.nbconvert_support”.

You have a configuration file that tries to import from the (not installed) jupyter_contrib_nbextensions package.

Check your environment for the installed Python packages either using pip or anaconda.

pip list | grep -i "jupyter-contrib-nbextensions"
conda list | grep -i "jupyter_contrib_nbextensions"

Ensure this package is installed. Otherwise, install the missing package.

Hi, I’m having a similar issue but with a different error message

  File "/home/paperspace/anaconda3/envs/fastai/lib/python3.6/json/decoder.py", line 357, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

I can’t open any .ipynb files. It always shows the message saying ‘500 : Internal Server Error’.
Does anybody know what is going on?