3.2 RPC Runtime Check Notes

The behavior of the client when methods are executed can be affected by the RPC protocol runtime checks and MIDL compiler options used when generating stubs. For example, this often concerns error codes when passing the NULL value in parameters with the [string] IDL attribute. In these cases, the IDL method does not return the expected error code. Instead, an RPC exception is raised.

For more information about generating RPC stubs from IDL definitions, see the topic "Using the MIDL Compiler" in [MSDN-MIDL].