1. In COpcDaServerWrapper.h COpcDaServerWrapper doesn't implement IOPCShutdown, then in COpcConnectionPoint.cpp OpcConnect() always returns E_FAIL for following code. IOPCShutdown should be added to class COpcDaServerWrapper implementation.

// connect
hResult = pCP->Advise(ipSink, pdwConnection);

    if (FAILED(hResult))
    {
        THROW();
    }

2. In COpcConnectionPoint.cpp, COpcConnectionPoint::Advise() has following code,

if (pContainer != NULL)
{
pContainer->OnAdvise(m_tInterface, dwCookie);
pContainer->Release();
}

return S_OK;

When pContainer->OnAdvise(m_tInterface, dwCookie) fails in calling IOPCShutdown, Advise() shouldn't still return S_OK to client. In this case it should E_FAIL or another HResult instead of S_OK.