Issues with Secondary Monitors
Firestorm Won't Open on My Secondary Monitor
If you have two (or more) monitors and prefer to use Firestorm on one other than the primary, move it over as you normally would; but before closing it the first time, make sure the window is NOT maximized. This will save the window position when you next go to start the viewer. On subsequent runs you can maximize the viewer.
Bake Fail
In some cases, running the viewer on a monitor other than the primary may result in a bake fail, or you may become invisible to yourself.
Firestorm Locks Up on "Initializing VFS"
There has been a report of someone getting this problem when opening the viewer on a secondary monitory rather than the primary. So if you're getting the problem, try opening the viewer on your primary monitor.
Black Screen with a Single Small Rectangle
A user reports that this is due to opening the viewer on a secondary monitor. However, others report that the problem was caused by a Windows update, and removing that update fixed the issue.