3825978 - Error: "One or more of the account numbers you entered has more than 14 characters [...]"

I am trying to insert the Frequent Flyer number / Mileage Program in the User Profile and I received the following warning:

One or more of the account numbers you entered are greater than 14
characters. This usually indicates an incorrect number. You may want to
review your entry(s) to make certain you have entered them exactly as
they appear on your card, without any additional characters, without
the carrier code, and without your name.
 
Click OK to save anyway; otherwise click Cancel to review your entries.

Error message when inserting a Frequent Flyer number in Profile. , KBA , CON-TRV-ADM-USR-PRO , Profile , Problem