Error in existing Apple ID when using Facetime on Mac Desktop Version
I have that same issue. If you already have an existing Apple ID...and when you try it...this error occurs.
The only solution is to create another Apple ID with my other email account.
When I create the new Apple ID, I had to conform with Apple way of password creation....WTF...need at least a Capital letter, not same letter thrice....man...big hassle...come on. my password is my password...Hope Apple don't put this restriction in their final.

yes. obviously apple's verification server is having issues, probably because of the high load.
I have that same issue. If you already have an existing Apple ID...and when you try it...this error occurs.
The only solution is to create another Apple ID with my other email account.
When I create the new Apple ID, I had to conform with Apple way of password creation....WTF...need at least a Capital letter, not same letter thrice....man...big hassle...come on. my password is my password...Hope Apple don't put this restriction in their final.