I have tried few link today, if you V4.17 running on wireless-NV2, Please do not upgrade to V5.0.
Cause if you do so, your wireless interface will be disable once you rebooted the routerboard.
then you need to travel and re-configure it again..
If you plan to upgrade to the V5.0, you have to disable the V4.17 wireless-NV2 package.
and let default run on wireless package.