> On EU side if airport personnel told you it's their flag, not the ESTA that is the issue.
> How frustrating. Whatever system the airlines are using it throws up erroneous flags, often.
The same thing happened two weeks ago to my boss, he had an ESTA permission issued until Nov 2018 but it got revoked without notice or reason and he only found out at the airport. He still doesn't know, even though he has an Official Passport (sometimes called Service Passport) and was on diplomatic mission to the UN climate conference in NY.
Might be that in this case the airline person just typed the wrong ESTA information and either didn't find it or found one that was rejected, or he simply just didn't file an ESTA or it was expired.
The whole system is somewhat archaic and outdated.
