2>game_engine.lib(Engine.obj) : error LNK2019: unresolved external symbol "public: void __thiscall std::_String_base::_Xran(void)const " (?_Xran@_String_base@std@@QBEXXZ) referenced in function "public: class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > & __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::assign(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,unsigned int,unsigned int)" (?assign@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QAEAAV12@ABV12@II@Z) 2>game_engine.lib(Script.obj) : error LNK2001: unresolved external symbol "public: void __thiscall std::_String_base::_Xran(void)const " (?_Xran@_String_base@std@@QBEXXZ) 2>game_engine.lib(Engine.obj) : error LNK2019: unresolved external symbol "public: void __thiscall std::_String_base::_Xlen(void)const " (?_Xlen@_String_base@std@@QBEXXZ) referenced in function "protected: bool __thiscall std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::_Grow(unsigned int,bool)" (?_Grow@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@IAE_NI_N@Z) 2>game_engine.lib(Script.obj) : error LNK2001: unresolved external symbol "public: void __thiscall std::_String_base::_Xlen(void)const " (?_Xlen@_String_base@std@@QBEXXZ)

oh, i am using .net 2005

i solved it. but still what does it mean?

You have linker errors (LNK*) because of the absence of a definition (unresolved external function) for "public: void __thiscall std::_String_base::_Xran(void)const" (a public, const, member function of std::_String_base named _Xran which takes no parameters and returns nothing). The rest is effectively meaningless (either telling you about the contexts in which this function is needed, or providing the full 'mangled' symbol names that the linker uses as unique IDs for the bits of code).

Presumably this is due to some misconfiguration of your compiler preventing it from including the string implmentation when linking.

thanks