Hello Every One,
please to fix the error 0x80070021
( Config Error: This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault="Deny"), or set explicitly by a location tag with overrideMode="Deny" or the legacy allowOverride="false". )
please follow below steps in this link:
http://support.pitneybowes.com/VFP06_KnowledgeWithSidebarTroubleshoot?id=kA280000000CiqcCAC&popup=false&lang=en_US