Rename a project

My dear friend,
Thank you. Can you please look into my problem about renaming a file? The way I do is as follows:
On the left-hand side bar at the top, the project name is shown. I partially or completely delete the name, moving the cursor over it and then typing the new name, It used to take the new name at least until 2 weeks ago. Today it does not take any name. I am 100% sure about it. No new name ia accepted. Is there another way to rename the project? Can you please save me from this trap?
Sincerely yours,
Ahammadunny Pathiaseril.
Ahammadunny@hotmail.com