Fixing “Unable to connect publishing custom string handler for output caching”

I was troubleshooting another issue on a client’s production server and ran across the following errors in the event log (Application Log).  The error was occurring on a KnowledgeLake Viewer web service.  After some quick searching I found Namwar Rizvi’s post on how to fix the problem.  It appears that SharePoint output caching is trying to access the web service that is called by a web part which is causing the error to occur.

Event Type:        Error

Event Source:        Office SharePoint Server

Event Category:        Publishing Cache

Event ID:        5785

Date:                9/2/2009

Time:                9:29:56 AM

User:                N/A

Computer:        <WebFrontEnd>


Unable to connect publishing custom string handler for output caching.  IIS Instance Id is ‘50319175’, Url is ‘’.


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