21406: Cannot set SmsFallbackUrl without setting SmsUrlPositive FeedbackNegative FeedbackERROR: 21406error-21406 page anchorPositive FeedbackNegative FeedbackERROR Error - 21406error---21406 page anchorPositive FeedbackNegative Feedback Cannot set SmsFallbackUrl without setting SmsUrlcannot-set-smsfallbackurl-without-setting-smsurl page anchorPositive FeedbackNegative FeedbackYou cannot set a fallback URL without specifying a primary URL