When logging on Comcast I keep getting a Blue Banner stating 75% complete setting, enter another email address or phone number. So Now What? I do not have another email address or another phone number? Most of the time I have to shut down and restart. I've called and emailed for support, never a response.
Like most other email providers, Comcast is now pushing for two-factor authorization on their accounts for better security. My account says the same thing yours does about the 75%. You need to enter either a cell phone number or an email address from some non-Comcast provider you have. Your account will continue to function without it, but at lower security levels. That is the reality of the internet now.