Flying LHR-BOS in Club tomorrow. Myself, Mr Gamebird and Mini Gamebird. Went to check in online this evening as always and all good for the husband and son, but against my name is the message "Sorry, we can’t check you in for this flight. Please go to the airport check-in desk."

A little background, we were originally flying on the 12th, but two days ago changed to tomorrow's flight (11th) when redemption availability opened up. The agent reissued the tickets there and then and allowed us to select our seats. All pretty standard. Saying that, there's been a red banner for a while saying that we need to add API, but I'd done this ages ago. I checked it and it's all in an correct, however the red banner is still there.

Slightly worried now! Anyone know why 2/3 passengers would be OK to OLCI but not the third? Insights and experiences welcome as always.