[MS Teams] HTTP Error [400 or 413] in outbound messages during Topic Discovery and Reference Choice Picker Currently Microsoft defines an upper limit of 28Kb on chat size per post. This can happen even if the choice is >=100 Any outbound payload from ServiceNow to MS Teams if > 28Kb overall, Microsoft will respond with HTTP error 400 or 413 - MessageSizeTooBig. Refer to this link from Microsoft for complete information. On the ServiceNow instance the same error can be tracked via 'Execution Details' for 'Virtual Agent - MS Teams Adapter Sender Subflow'. Refer to this link on how to enable reporting for subflows in ServiceNow instance. Attached is a sample screenshot from execution details. Workaround - Its an upper limit from Microsoft. There is no workaround.