This morning I checked my husband and I into our flight(s) tomorrow. I was able to check him in without any issues and get his boarding assignment. For my connecting flight, I recieved a message saying "Airport Checkin Required". I fly for work fairly often and have always been able to check in online without an issue. Has anyone experienced this before? I'd hate to get to my connecting airport to realize it's something major.
This usually occurs if you book a special fare such as a senior or child fare that requires age verification. I think it's also possible if all standard boarding positions have already been assigned and the system can't assign you a position. In this case the gate agent will be able to assign you a position. Last option I can think of is if you have a connecting flight, one flight might be cancelled or rescheduled, but if your husband has the same itinerary this shouldn't be a problem. You can use the flight status tool on southwest.com to check the flights.
If you don't think you have a special fare that requires verification you could try checking in again closer to departure time when a boarding position might have opened up (if that's the problem).
Please report back and let us know what the issue was.