No Mouse Cursor - Vorpx Incompatibility
If your mouse cursor becomes invisible when running Firestorm, check to see if you have the Vorpx driver for Rift installed. Thsi is known to create issues with software it does not recognize.
Vorpx suggest doing one of the following:
Exit vorpX Control (right click tray icon, choose “Exit”).
Pause the watcher (right click tray icon, choose “Pause watcher”).
Add applications to the exclude list in the vorpX config app
Ref. Bug: Adversely affects Second Life and Firestorm Viewer and FIRE-14354.