Error during user sync : System.InvalidOperationException: There is an error in XML document (0, 0). ---> System.Xml.XmlException: Root element is missing
Cause
This file <StonevoiceAS>\Apps\Fw\Report\FW.Sync.Reporting.xml is empty
Solution
In order to fix the issue, delete this file:
<StonevoiceAS>\Apps\Fw\Report\FW.Sync.Reporting.xml
then attempt users syncronization again.