The sendDigits attribute may contain numbers, the # and * characters, the letters A, B, C, D, as well as lowercase w to "wait" for half a second or uppercase W to "wait" for a full second. See the Dial Verb API Reference for more information.
The attribute sendDigits includes an invalid character.
Ensure the sendDigits attribute only contains the characters: 0123456789ABCD*#wW.