Using Terminal Server when you are going to do a click in FNU CampusVUE link:
The first time you must need to do the following steps:
1) Click on Detect Receiver
2) Select the checkbox : "Always allow https://cvue.fnu.edu to open receiver links", and click on Choose Application.
3) Select the checkbox: "Always use this application to open receiver links" and click on Open Link.
After these steps you are able to open FNU CampusVUE in Firefox.