Nikolay Sivov (@nsivov) commented about dlls/ntdll/actctx.c:
ACTIVATION_CONTEXT_STACK *actctx_stack = teb->ActivationContextStackPointer; RTL_ACTIVATION_CONTEXT_STACK_FRAME *frame;
- if (flags != 0)
return STATUS_INVALID_PARAMETER;
We don't need that change, and it's not clear if it's correct.