I cant access router login page or internet Nighthawk R8000 or R9000

So i used to use N Hawk R8000, about a year ago i stoped using it still worked but i went to modem only for personal reasons, forward to last week i went and tried to connect the N hawk R8000 and all was fine the Genie popped up it even let me login with the old Password so im in the process of trying to change the password and i was trying to think of a new password when all of a sudden this small window pops up asking for my password so i typed in the one i used 3 minutes before but it didnt work and the the genie diaspeared and there was nothing there.

So I tried all the suggestions that the install/support pages gives you factory reset, 192.168...., connecting through router only and i cant remember the rest, so dummy me I purchased the N Hawk R9000 thinking I might have busted the R8000, but still no solution, some help would be cool, thanks