Hi there!!! Now I'm trying to include the boost serialization library on my project through class derivation. I've followed the demo_fast_archive.cpp and the binary serialization is compiling and working fine. Now I'me trying to make the same for the text serialization and then for the xml serialization. But when compiling I'm getting these link errors: Linking... Creating library ..\..\Bin\silvestre.lib and object ..\..\Bin\silvestre.exp main2.obj : error LNK2019: unresolved external symbol "public: __thiscall boost::archive::text_oarchive_impl<class FlowEngine::TextArchiveO>::text_oarchive_impl<class FlowEngine::TextArchiveO>(class std::basic_ostream<char,struct std::char_traits<char> > &,unsigned int)" ( ??0?$text_oarchive_impl@VTextArchiveO@FlowEngine@@@archive@boost@@QAE@AAV?$basic_ostream@DU?$char_traits@D@std@@@std@@I@Z) referenced in function "public: __thiscall FlowEngine::TextArchiveO::TextArchiveO(class std::basic_ostream<char,struct std::char_traits<char> > &,unsigned int)" ( ??0TextArchiveO@FlowEngine@@QAE@AAV?$basic_ostream@DU?$char_traits@D@std@@@std@@I@Z ) main2.obj : error LNK2019: unresolved external symbol "public: __thiscall boost::archive::text_iarchive_impl<class FlowEngine::TextArchiveI>::text_iarchive_impl<class FlowEngine::TextArchiveI>(class std::basic_istream<char,struct std::char_traits<char> > &,unsigned int)" ( ??0?$text_iarchive_impl@VTextArchiveI@FlowEngine@@@archive@boost@@QAE@AAV?$basic_istream@DU?$char_traits@D@std@@@std@@I@Z) referenced in function "public: __thiscall FlowEngine::TextArchiveI::TextArchiveI(class std::basic_istream<char,struct std::char_traits<char> > &,unsigned int)" ( ??0TextArchiveI@FlowEngine@@QAE@AAV?$basic_istream@DU?$char_traits@D@std@@@std@@I@Z ) main2.obj : error LNK2019: unresolved external symbol "public: void __thiscall boost::archive::text_iarchive_impl<class FlowEngine::TextArchiveI>::load_override(struct boost::archive::class_name_type &,int)" ( ?load_override@?$text_iarchive_impl@VTextArchiveI@FlowEngine@@@archive@boost@@QAEXAAUclass_name_type@23@H@Z) referenced in function "protected: void __thiscall FlowEngine::TextArchiveI::load_override<struct boost::archive::class_name_type>(struct boost::archive::class_name_type &,int)" ( ??$load_override@Uclass_name_type@archive@boost@@@TextArchiveI@FlowEngine@@IAEXAAUclass_name_type@archive@boost@@H@Z ) main2.obj : error LNK2019: unresolved external symbol "public: void __thiscall boost::archive::text_oarchive_impl<class FlowEngine::TextArchiveO>::save(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" ( ?save@?$text_oarchive_impl@VTextArchiveO@FlowEngine@@@archive@boost@@QAEXABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "public: static void __cdecl boost::archive::save_access::save_primitive<class FlowEngine::TextArchiveO,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >(class FlowEngine::TextArchiveO &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" ( ??$save_primitive@VTextArchiveO@FlowEngine@@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@save_access@archive@boost@@SAXAAVTextArchiveO@FlowEngine@@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z ) ..\..\Bin\silvestre.exe : fatal error LNK1120: 4 unresolved externals Error executing link.exe (tool returned code: 1120) silvestre - 5 error(s), 0 warning(s) For a better understand of the problem I'm going to attach the source files Note that I've not tested/look XMLSerialization.h, so it must have errors to I guess.. -- Miguel Silvestre