Versions of Sage 100 prior to 4.4 required a separate Pocket Soap program download to complete the integration with Sage 100.
Pocket SOAP is the open source Clint communication components for the windows family. It supports for SOAP 1.1 and soap 1.2. It supports attachment via Both DIME and SOAP.
As of version 4.4 this download is no longer required.
Resolution:
No separate download is required.
Versions prior to 4.4 which need Pocketsoap should reference this link