3631949 - Error "401 Unauthorized – Invalid Authorization" when using SMS-Based Two-Factor Authentication via Sinch in SAP Cloud Identity Services

Users attempting to log into SAP systems using SMS-based Two-Factor Authentication (2FA), configured through the Sinch service in SAP Cloud Identity Services, encounter the following error message:

• Error Message: "Failed to send sms code to user:[*****] with phone:[****], Exception info:[401 Unauthorized: '{'errorCode':40100,'message':'Invalid authorization.','reference':' '}'], Cause: [null] 401 Unauthorized: '{'errorCode':40100,'message':'Invalid authorization.','reference':''}' Correlation ID: XXXXXXXX-YYYY-ZZZZ-AAAA-BBBBBBBBBBBB" 

SAP Cloud Identity Services

Two-Factor Authentication, SMS, Sinch, 401 Unauthorized, Invalid Authorization, Verification Code, Cloud Identity Services , KBA , BC-IAM-IDS , Identity Authentication Service , Problem