TdhGetEventInformation return 1168 (NOT FOUND) - How PerfView can get the info?

Question

I have a ETL file and I am trying to parse it with OpenTrace and get the information with TdhGetEventInformation when I get the callback EventRecordCallback.

However, for the provider that I need, it always return 1168 (NOT FOUND). The only way it works is by loading the manifest with TdhLoadManifest, this way I get all the information. But I don't understand how WPA and PerfView can get all the events for my provider even when I am not providing the manifest...

I found that the TDH.dll has some undocumented functions that PerfView uses like TdhGetAllEventsInformation, I tried to use this function by loading the DLL with LoadLibraryEx, the function again return 1168..

Following code is mostly by Microsoft samples:

DWORD status = ERROR_SUCCESS;
DWORD BufferSize = 0;
status = TdhGetEventInformation(pEvent, 0, nullptr, pInfo, &BufferSize);

if (1168 == status)
    return status; // THIS 

if (ERROR_INSUFFICIENT_BUFFER == status)
{
    pInfo = (TRACE_EVENT_INFO*)malloc(BufferSize);
    ZeroMemory(pInfo, BufferSize);
    if (pInfo == NULL)
    {
        LogPrintError(L"Failed to allocate memory for event info (size=%lu).\n", BufferSize);
        status = ERROR_OUTOFMEMORY;
        goto cleanup;
    }

    // Retrieve the event metadata.

    status = TdhGetEventInformation(pEvent, 0, NULL, pInfo, &BufferSize);
}

I really want to know how PerfView get this information without the manifest. So far I see they use TdhGetAllEventsInformation but I keep receiving 1168, I am missing something?

Thanks.