Get in trouble in creat a new file in jupyter nootbooks and edit the previous file

I can’t create a new file in the Jupyter notebook, and when I open an old file, I can’t edit it anymore. Also, I tried to reinstall the app several times, but without success. I also reinstalled the python operating environment (3.9). In addition to the problems I mentioned above, I have not encountered any other aspects of the software running problems, they are normal.