Symptoms

Client is using a SmartObject event to update a list on SharePoint. When trying to set the DateTime property type to Null or EmptyString, mapping throws an error "Ensure that the value corresponds to data type."
 

Diagnoses

Was able to replicate the issue on a VM. Changed the SmartObject event to use a SharePoint 2013 List Event > Update List option and was able to set the DateTime parameter to Null/Empty String without issue.
 

Resolution

Client tested the SharePoint 2013 List Event > Update List option and was able to set the parameter to EmptyString.