21656: The ContentVariables Parameter is invalidERROR: 21656error-21656 page anchorPROGRAMMABLE SMSERROR Descriptiondescription page anchorThe ContentVariables Parameter is invalid Possible Causespossible-causes page anchorThe ContentVariables Parameter is not a JSON String Possible Solutionspossible-solutions page anchorValidate the ContentVariables Parameter, it must be a JSON String