Running a web app but not able to navigate in side it

I have this web application up and running in my localhost but all im able to do at this stage is login into it. There is this tab that when clicked, will take me to a page with lots of other options and so on...but im not able to do any of that! The error that im getting is, Failed to load resource : the server responded with a status of 404(not found). As far as i know, the server has no issues and it is up and running(i dont have anything to do with the server-side coding by the way). Can someone please guide me as to what could be wrong?

This app uses gulp as the build tool. Thanks in advance!