Wt

Any help with this would be much appreciated.
Is there a known conflict between the Wt and Qt Signal classes? I periodically get the following compliation error which is sometimes resolved by changing header inclusion orders - but not always.
Does anyone have any hints as to how this can be resolved in general?

In file included from /usr/local/include/Wt/WSignal.h:14,
from /usr/local/include/Wt/WResource.h:12,
from ../../lfrServer/src/LfrApi.h:6,
from ../../lfrServer/src/LfrApi.cpp:10:
/usr/local/include/Wt/Signals/signals.hpp:218:18: error: expected ‘)’ before ‘...’ token
218 | void emit (Args... args) const
| ~ ^~~
| )
/usr/local/include/Wt/WSignal.h:329:14: error: expected ‘)’ before ‘...’ token
329 | void emit(A... args) const;
| ~ ^~~
| )
/usr/local/include/Wt/WSignal.h:661:14: error: expected ‘)’ before ‘e’
661 | void emit(E e = NoClass()) const;
| ~ ^~
| )
/usr/local/include/Wt/WSignal.h:761:24: error: expected unqualified-id before ‘(’ token
761 | void Signal<A...>::emit(A... args) const
| ^
/usr/local/include/Wt/WSignal.h: In member function ‘void Wt::Signal<A>::operator()(A ...) const’:
/usr/local/include/Wt/WSignal.h:769:12: error: expected ‘)’ before ‘...’ token
769 | emit(args...);
| ~ ^~~


... etc