I received the following error in the group hub while testing the solution build in Microsoft tutorial 3, lesson 3: “Failed while creating a B2BOrchestrations.B2BProcess service”
After 30 minutes I finally found the solution. BizTalk does not refresh the new deployment automatically. You should first restart the BizTalkServerApplication Host instance from the “Platform Settings - Host Instances” node in the BizTalk Server 2006 Administration Console.
If that did not do the trick, you can also try to remove the orchestration from the GAC, redeploy it and then refresh the BizTalkServerApplication Host instance.