I upgraded recently every single Python lib on my computer, and I am not able to convert my Notebooks from the File Menu from Jupyter. I get the message:
500 : Internal Server Error
The error was:
nbconvert failed: '.\cumulative chart (for ANE17 poster).ipynb' exists but is not a directory
It is fine for me to convert through the command line, and actually this works:
[NbConvertApp] Converting notebook .\cumulative chart (for ANE17 poster).ipynb to pdf
[NbConvertApp] Support files will be in cumulative chart (for ANE17 poster)_files\
[NbConvertApp] Making directory .\cumulative chart (for ANE17 poster)_files
[NbConvertApp] Making directory .\cumulative chart (for ANE17 poster)_files
[NbConvertApp] Writing 26403 bytes to .\notebook.tex
[NbConvertApp] Building PDF
[NbConvertApp] Running xelatex 3 times: ['xelatex', '.\\notebook.tex']
[NbConvertApp] Running bibtex 1 time: ['bibtex', '.\\notebook']
[NbConvertApp] WARNING | b had problems, most likely because there were no citations
[NbConvertApp] PDF successfully created
[NbConvertApp] Writing 43091 bytes to .\cumulative chart (for ANE17 poster).pdf
But still, what happened to Jupyter, and/or nbconvert, and/or the Pandoc/MiKTex lib? Thank you for your input
Actually, I had the same problem after Jupyter re-installation. According to this page, it's a bug in recent versions of notebook package starting from 5.2, which should be fixed in later versions. Currently, the solution would be just to downgrade the notebook package, like:
pip install -U "notebook<5.2"
At least it worked for me.