Jupyter Notebook not saving: '_xsrf' argument missing from post

I've been running a script on jupyter notebooks for about 26 hour; I haven't really been using my computer for anything else, but it needs to run this program that will take ~30 hours to complete. At about 21 hours in, it stopped saving and my terminal had this:

403 PUT /api/contents/[file.ipynb] (::1): '_xsrf' argument missing from POST

where [file.ipynb] is the location of my jupyter notebook. It also says:

'_xsrf' argument missing from post

in the top right part of the notebook again. The program is still running and I don't want to restart jupyter notebook and have to run the program again, as I have a deadline, is there anything else I can do?

I'm using google chrome, but I don't have the LastPass extension or any '%' characters in my code, as another post suggested.

Thanks for any help!

The easiest way I found is this:

https://github.com/nteract/hydrogen/issues/922#issuecomment-405456346

Just open another (non-running, existing) notebook on the same kernel, and the issue is magically gone; you can again save the notebooks that were previously showing the _xsrf error.

If you have already closed the Jupyter home page, you can find a link to it on the terminal from which Jupyter was started.

The solution I came across seems too simple but it worked. Go to the /tree aka Jupyter home page and refresh the browser. Worked.

The only solution worked for me was:

1. I opened a new tab in chrome
2. I pasted : http://localhost:8888/?token=......
3. then I went to my original notebook and I was able to save it

I use jupyter notebooks daily and had never experienced this issue before... until today. I had the notebook open all day but it wasn't running anything and then for no apparent reason stopped auto-saving with the '_xsrf' argument missing from POST error message in the top right. FYI - this is a python3 notebook.

I don't know the cause of this problem but I have recently upgraded my python3 version to 3.7.2 and upgraded all of my site-packages to their latest version as of a few days ago which could possibly be the cause.

As for a solution, as suggested in the comment by @AlexK, I opened the same notebook in a new window (different browser in fact), using

jupyter notebook list

in the terminal to get the URL with login token.

This resulted in me having the notebook open and savable again but the information I had entered since the last successful auto-save was missing. Thankfully, my broken instance was still open and working apart from saving so I was able to simply copy and paste the information across then hit save. So, keep the broken instance open if you try this!

When I click 'save' button, it has this error. Based on the answers in this post and other websites, I just found the solution. My jupyter notebook is installed from pip. So I access it by typing 'jupyter notebook' in the windows command line.

(1) open a new command window, then open a new jupyter notebook. try to save again in the old notebook, this time ,the error is 'fail: forbidden'

(2) Then in the old notebook, click 'download as', it will pop out a new windows ask you the token.

(3) open another command window, then open another jupyter notebook, type 'jupyter notebook list' copy the code after 'token=' and before :: to the box you just saw. You can save this time. If it fails, you can try another token in the list