warning C6103: Returning <variable> from failed function call at line <location>.
A successful path through the function is returning a variable that was used as an _Out_ parameter to an internal function call that failed.
The problem might be that the called function and the calling function are not completely annotated. The called function may require _Always_, _Outptr_result_nullonfailure_ (_COM_Outptr_ for COM code), or a related annotation, and the calling function may require a _Success_ annotation. Another possible cause for this warning is that the _Success_ annotation on the called function is incorrect.