Detailed Instructions: Given a travel related situation, and given a specific question about the situation, summarize the question into a title
Q: I have an ESTA for the US, valid until Mar 20, 2020. I have confirmed the ESTA is still valid on the U.S. Customs and Border Protection site. However, the airline I have a flight booked with will not allow me to check in online due to not having a valid ESTA/VISA/etc.

Does this mean I'm not going to be allowed on the flight or is it simply a problem with the online check-in? And if I'm allowed on the flight, should I expect issues on arrival in the US?

A:
Valid ESTA for US, but not allowed to check-in Online