Unable to login via nighthawk

[yeshwanth]

Unable to authenticate or login via nighthawk app, unable to authenticate gateway of provider as nighthawk not logging in, getting serial number already registered error

[plemans]

You didn't give us much to go off. 

you have the R6120? 

What firmware is on it? 

What modem/gateway is it connected to? 

You're having issues logging into it? 

Have you tried factory rsetting it and reinstalling it? 

push and hold reset for 7-15 seconds while its powered on and then follow the install guide. 

https://www.netgear.com/support/product/r6120