3823423 - Error AADSTS50105 - Your Administrator has configured the application SAP Concur Travel and Expense to block users unless they are specifically granted access to the application

One of our users is trying to log into SAP Concur via Single Sign On (SSO) but is receiving the following error message:

Sorry, but we're having trouble signing you in.
AADSTS50105: Your Administrator has configured the application SAP Concur Travel and Expense to block users unless they are specifically granted ('assigned') access to the application. The signed in user XXXXXX@XXX.com is blocked because they are not a direct member of a group with access, nor had access directly assigned by an administrator. Please contact your administrator to assign access to this application.
 

KBA , CON-EXP-EXP , Expenses , CON-CA-ADM-AUA-MMS , Manage Mobile Sign-On , Problem