My Jupiter NB has error

I am trying to rename the JupiterNB file name to another name and when I am refreshing the webpage it is saying 404 : Not Found You are requesting a page that does not exist! on the JupiterNB Lab.
What is yours advice to solving my problem ? It is so confusing me to this lab.

Yes, there needs to be a notebook that has the name expected by the “Work in Browser” link. You can get a new copy by following the instructions in the first topic on the FAQ Thread.