3824806 - Why am I receiving the error: "Warning returned during shop: PROFILE_VALIDATION_FAILED" while making my reservation?

While attempting to add a hotel to an existing reservation, the traveler received an error that prevented them from completing their trip.  The displayed error was that one or more required fields were missing from the profile, yet, when viewing the traveler profile, all required fields appear to be completed.

The traveler is receiving a booking error on the Review and Book page, "One or more required fields are missing from your profile. Please add the required fields. Once completed you will be redirected back to this page" which prevents them from placing their reservation in Concur. , KBA , CON-MOB-TRV-HTL , Hotel , CON-CA-USP , User Profile , CON-SRV-TRV-SBR , TwsSabre Test , Problem