If you're not able to start up VisualRF from VisualRF Setup, then that means there's probably another issue happening in the background. If the problem is persisting, I suggest opening a support case so that a TAC engineer can help diagnose the issue.
What AMP version are you currently running? (you should be running at least 8.0.8.1)
Any errors in /var/log/visualrf/visualrf.log?