Issues with editing bibliography font

I finished my literature review paper yesterday and moved onto my next project. Today, each time I tried to change the font of the references from bibliography of the last paper, it says “can not be formatted because it is no longer open. Please choose another document.” (already uploaded the screenshot).
What is the problem?
Btw, I changed the file name. Is it because of that?

Have you tried to find the document from the drop down?

Try to close that window and use the “go to Endnote” from the endnote ribbon - and see if it now is going from your document. and the document is showing up in the bibliography menu.

Why are you having to change the font in your bibliography? It should be automatic based on the underlying word templates?