Error?

I already contributed to this post earlier this week, but I can also confirm the same frustrations that others have voiced this week. Just today, I was able to get two users that were seeing this error to book by trying in an Incognito window in Chrome. As others pointed out, we had them book "as Guest" and they had to verify with a 6-digit code emailed to them, but it was able to work without error. Hope this helps others try, but I agree, Microsoft needs to listen and fix this.