Hi, I'm getting a strange error in that I've done this before without problems. But I've started a new MFC project and I'm getting this error. The same exact header in other projects compiles fine. I'm using all the same settings. with:  auto* facet= new boost::posix_time::time_facet( "%d-%b-%Y %H:%M:%S" ); and if I comment that line the same error comes in further down where I:     os << "[" << boost::posix_time::second_clock::local_time() << "] "; I just can not figure out what is different in this project that is causing this. using the latest MS compiler with c++17 Thanks, Dan. I'm getting: F:\cpp\boost_1_74_0\boost\algorithm\string\replace.hpp(654,37): error C2672: 'boost::algorithm::first_finder': no matching overloaded function found 1>F:\cpp\boost_1_74_0\boost\date_time\time_facet.hpp(312): message : see reference to function template instantiation 'void boost::algorithm::replace_all<std::basic_string<char,std::char_traits<char>,std::allocator<char>>,const char*,std::basic_string<char,std::char_traits<char>,std::allocator<char>>>(SequenceT &,const Range1T &,const Range2T &)' being compiled 1>        with 1>        [ 1> SequenceT=std::basic_string<char,std::char_traits<char>,std::allocator<char>>, 1>            Range1T=const char *, 1> Range2T=std::basic_string<char,std::char_traits<char>,std::allocator<char>> 1>        ] 1>F:\cpp\boost_1_74_0\boost\date_time\time_facet.hpp(285): message : while compiling class template member function 'OutItrT boost::date_time::time_facet<boost::posix_time::ptime,char,OutItrT>::put(OutItrT,std::ios_base &,char,const time_type &) const' 1>        with 1>        [ 1> OutItrT=std::ostreambuf_iterator<char,std::char_traits<char>>, 1>            time_type=boost::posix_time::ptime 1>        ] 1>F:\cpp\boost_1_74_0\boost\date_time\posix_time\posix_time_io.hpp(52): message : see reference to function template instantiation 'OutItrT boost::date_time::time_facet<boost::posix_time::ptime,char,OutItrT>::put(OutItrT,std::ios_base &,char,const time_type &) const' being compiled 1>        with 1>        [ 1> OutItrT=std::ostreambuf_iterator<char,std::char_traits<char>>, 1>            time_type=boost::posix_time::ptime 1>        ] 1>f:\cpp\include\logging.h(20): message : see reference to class template instantiation 'boost::date_time::time_facet<boost::posix_time::ptime,char,std::ostreambuf_iterator<char,std::char_traits<char>>>' being compiled 1>F:\cpp\boost_1_74_0\boost\algorithm\string\replace.hpp(654,1): error C2893: Failed to specialize function template 'boost::algorithm::detail::first_finderF<range_const_iterator<T,void>::type,boost::algorithm::is_equal> boost::algorithm::first_finder(const RangeT &)' 1>F:\cpp\boost_1_74_0\boost\algorithm\string\finder.hpp(52): message : see declaration of 'boost::algorithm::first_finder' 1>F:\cpp\boost_1_74_0\boost\algorithm\string\replace.hpp(654,1): message : With the following template arguments: 1>F:\cpp\boost_1_74_0\boost\algorithm\string\replace.hpp(654,1): message : 'RangeT=Range1T' 1>F:\cpp\boost_1_74_0\boost\algorithm\string\replace.hpp(652,33): error C2672: 'boost::algorithm::find_format_all': no matching overloaded function found 1>F:\cpp\boost_1_74_0\boost\algorithm\string\replace.hpp(655,1): error C2780: 'void boost::algorithm::find_format_all(SequenceT &,FinderT,FormatterT)': expects 3 arguments - 2 provided 1>F:\cpp\boost_1_74_0\boost\algorithm\string\find_format.hpp(250): message : see declaration of 'boost::algorithm::find_format_all' 1>F:\cpp\boost_1_74_0\boost\algorithm\string\erase.hpp(595,37): error C2672: 'boost::algorithm::first_finder': no matching overloaded function found 1>F:\cpp\boost_1_74_0\boost\date_time\time_facet.hpp(321): message : see reference to function template instantiation 'void boost::algorithm::erase_all<std::basic_string<char,std::char_traits<char>,std::allocator<char>>,const char*>(SequenceT &,const RangeT &)' being compiled 1>        with 1>        [ 1> SequenceT=std::basic_string<char,std::char_traits<char>,std::allocator<char>>, 1>            RangeT=const char * 1>        ] 1>F:\cpp\boost_1_74_0\boost\algorithm\string\erase.hpp(595,1): error C2893: Failed to specialize function template 'boost::algorithm::detail::first_finderF<range_const_iterator<T,void>::type,boost::algorithm::is_equal> boost::algorithm::first_finder(const RangeT &)' 1>F:\cpp\boost_1_74_0\boost\algorithm\string\finder.hpp(52): message : see declaration of 'boost::algorithm::first_finder' 1>F:\cpp\boost_1_74_0\boost\algorithm\string\erase.hpp(595,1): message : With the following template arguments: 1>F:\cpp\boost_1_74_0\boost\algorithm\string\erase.hpp(595,1): message : 'RangeT=RangeT' 1>F:\cpp\boost_1_74_0\boost\algorithm\string\erase.hpp(593,33): error C2672: 'boost::algorithm::find_format_all': no matching overloaded function found 1>F:\cpp\boost_1_74_0\boost\algorithm\string\erase.hpp(596,1): error C2780: 'void boost::algorithm::find_format_all(SequenceT &,FinderT,FormatterT)': expects 3 arguments - 2 provided 1>F:\cpp\boost_1_74_0\boost\algorithm\string\find_format.hpp(250): message : see declaration of 'boost::algorithm::find_format_all'