Can not connect ring doorbell2 to router

Hello everyone, I am trying to setup the ring doorbell 2. I keep getting the left flashing lights on the device. My router is set to the lowest settings. I was able to connect to the router before but now I have no luck. Are there any settings on my router that need to be change. It's at the lowest firewall settting and the roter password is 8 charachters (no special characters). My door bell is right next to the router. Please help!