when you try to resubmit a message using the ESB portal you might get an error like “The resubmission failed: 500 – InternalServerError“. Upon inspecting the application event log you might see “There was a failure executing the receive pipeline: “Microsoft.BizTalk.DefaultPipelines.XMLReceive, Microsoft.BizTalk.DefaultPipelines, Version=3.0.1.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35” Source: “XML disassembler” Receive Port: “……” URI: “……..” Reason: The document specification <……….> from assembly <……….> failed to load. Verify the schema for this document specification is deployed and is in the Global Assembly Cache. “
I faced the same problem, I checked everything and everything looked fine. Finally the reason for this error is that the Application pool associated with the HTTP Application in IIS was V2.0 instead of V4.0.
I changed it to V.4.0 and the resubmission succeeded