4f55f5cb_ISDN_Cause_Codes__Cause_Usage
[Cause#] 96 [Fixit!] N/A [Cause Summary] Mandatory information element is missing. [Cause Usage] 
Indicates that the equipment sending this cause has received a message that is missing an information element that must be present in the message before that message can be processed.
ISDN Cause Codes
Cause Usage