The most frequent case where this issue is happening is when there is an INF (INFANT) passenger in the Booking.
Airlink works in a way where they add the INF to the first ADT in the Booking which causes their Title+FirstName+LastName to combine causing too many characters in one single line.
Airlink does not permit this so they give us this specific Error.
Resolution:
Most common way to resolve this is to change the First Passenger to someone with a shorter name and try it that way. If this is not possible, contact Support to check with Airlink regarding this and how it can be resolved.