VPN connection is failing with error "FlushIpNetTable failed on interface"
Andrew Henderson 
I originally had something called NCP Secure Entry sitting around installed on my computer but never used it. For this particular situation it was indicated that I should use a client called WatchGuard Mobile VPN. Things were working fine but then I figured I should uninstall the NCP client since it was unneeded.
Well that was a bad idea. This thing's uninstaller was a piece of garbage and apparently messed up every network adapter there was. I now only get errors when attempting to use WatchGuard. For information's sake, I believe WatchGuard is built on top of OpenVPN.
The first error is
NOTE: FlushIpNetTable failed on interface [3] {2AADF55B-9855-4BED-BF22-EAB9902A8D93} (status=1168) : Element not found.It then fires off these logs a bunch of times
2017-06-14T16:06:27.812 OVPN:>LOG:1497481587,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:27.815 OVPN:>LOG:1497481587,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:28.900 OVPN:>LOG:1497481588,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:28.903 OVPN:>LOG:1497481588,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:29.989 OVPN:>LOG:1497481589,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:29.992 OVPN:>LOG:1497481589,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:31.078 OVPN:>LOG:1497481591,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:31.081 OVPN:>LOG:1497481591,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:32.166 OVPN:>LOG:1497481592,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:32.169 OVPN:>LOG:1497481592,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:33.254 OVPN:>LOG:1497481593,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:33.257 OVPN:>LOG:1497481593,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:34.342 OVPN:>LOG:1497481594,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:34.345 OVPN:>LOG:1497481594,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:35.434 OVPN:>LOG:1497481595,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:35.437 OVPN:>LOG:1497481595,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:36.526 OVPN:>LOG:1497481596,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:36.529 OVPN:>LOG:1497481596,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:37.614 OVPN:>LOG:1497481597,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:37.617 OVPN:>LOG:1497481597,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:38.882 OVPN:>LOG:1497481598,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:38.885 OVPN:>LOG:1497481598,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:40.091 OVPN:>LOG:1497481600,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:40.094 OVPN:>LOG:1497481600,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:41.309 OVPN:>LOG:1497481601,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:41.312 OVPN:>LOG:1497481601,,Route: Waiting for TUN/TAP interface to come up...
2017-06-14T16:06:42.578 OVPN:>LOG:1497481602,,TEST ROUTES: 0/1 succeeded len=0 ret=0 a=0 u/d=up
2017-06-14T16:06:42.581 OVPN:>LOG:1497481602,,Route: Waiting for TUN/TAP interface to come up...And then finally
W,Warning: route gateway is not reachable on any active network adapters: 192.168.123.1
...
I,Initialization Sequence Completed With Errors ( see )I've tried a whole bunch of resets of adapters, reinstalling the TAP adapter and so on. No joy so far.
1 Answer
Ah well, appears I've cracked it. I'm not entirely sure what I did to fix it, but it looks like NCP had installed some sort of filter onto the adapter which was breaking everything.
Just go to Control Panel\All Control Panel Items\Network Connections and right click on the adapter -> properties. Look for an item called NCP Filter and uninstall it.
