Resolving HTTP Adapter Registration Error in AS2 BizTalk

When hosting the HTTP Endpoint in IIS for the AS2 adapter, BizTalk may fail to register the HTTP adapter and report an error such as:

The Messaging Engine failed to register an adapter "HTTP". Details: "Registering multiple adapter types within the same process is not a supported configuration. For e.g. HTTP and SOAP receive adapters cannot co-exist in the same process"

This error happens as a result of sharing an application pool with another adapter, particularly a web service, which conflicts with the configuration of the AS2 adapter. As is briefly described in this MSDN article, if this error occurs, consider separating a separate application pool for each adapter.