Yes, but there were "C++17 compliant(ish)" and "really C++17 compliant" versions of stdlibs. Scintilla didn't start using threading and futures and other concurrency features until these latest few versions, and older libraries might not support them. At least thats the only reason I can think of that it gives the current errors. But as I said `Mutex` is C++11 so it really should work by now.