How do I stop “invalid server error”

[Rvmbo]

Get this error every time I try to log in or go onto the duma os app. 
Requiring me to reboot my router each time before gaming

i also cannot add port forward as I get unknown error

i applied DMz of my router in my isp. Get open NAT type. 
Any help? Losing faith at this point

[Aspect of Wrath]

Try not using portforward/DMZ and just use upnp until next firmware, i think PF/DMZ are causing the issue. 

[Netduma Fraser]

Sounds like you've put a device in the DMZ on the R3 which will be why you're getting a port forward error, you can't do both. Disable IPv6 in LAN/WAN as that can help with the invalid issue.

[Rvmbo]

Which would you prefer keeping dmz enabled in my ISP setting? Or just disabling it and add port forwards to the R3 to get open nat type still?

[Netduma Fraser]

The R3 should be in the ISP router DMZ to get an Open NAT yes. You can then use port forwarding on DMZ on the R3 for your console, you don't need both, just one or the other