Missing File / Error Messages When Using Hyperlink

I am attempting to access a file which has not been deleted. 

The file is not visible/discoverable in my account, and when I attempt to use a hyperlink for the file, I am met with one of two messages, see below: 

• Oops! We can't seem to find the page you're looking for.

• Office Online failed to load.
  The Office Online Server is currently not responding.

Please advise what needs to be done in order to restore access to this file as it is a critical tracking document for an active project within our organization. 

Thanks