Michel the reason for this is that you didn't build the SessionInfoClient COM dll See on the SOAP user guide advance samples using soap headers you need to build the serverheaderhandler and the clientheaderhandle.

>While investigating on manipulating a SOAP header, I found various Microsoft examples that I can't run. For example, the folling should create a SessionInfoClient object.
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>loUniversalThread.HeaderHandler=CreateObject('SessionInfoClient.ClientHeaderHandler')
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>Whenever I try that it says class definition not found.
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>Is this doc still valid?