WatchESPN authentication fails

[SBK2]

I am a new Verizon FIOS customer and I am not yet able to authenticate on WatchESPN. How much time would it takes for my credentials to be propageted to WatchESPN service?

[BajaAlta]

Are you a brand new FiOS subscriber who just went through the installation process, or did you perhaps just add FiOS TV to an existing Verizon set of services?

[ipilcher]

AFAICT the answer is forever.  It's never worked for me with any web browser/OS combination.  Verizon technical support has been exactly as helpful as you would expect.

[CRobGauth]

Not to rehash it, but are you using the same email address as the primary account?

[doofus]

I have been a FioS subscriber for many years and was able to log into WatchESPN on my laptop until recently.  Now I get the same authentication error every time.  Username and password are correct and the app works fine on my phone.