Where is my error (Link)

Hello ...

I am not that talented, I must confess. I just tried QuickGUI10.8 package, and I am facing a problem on the demo .
When I try to compile the project, I have these messages:

Creating library C:\Ogre\QuickGUI_10_8\QuickGUIOgreDemo\\bin\QuickGUIOgreDemo.lib and object C:\Ogre\QuickGUI_10_8\QuickGUIOgreDemo\\bin\QuickGUIOgreDemo.exp
1>main.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::FontManager * QuickGUI::Singleton<class QuickGUI::FontManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VFontManager@QuickGUI@@@QuickGUI@@1PAVFontManager@2@A)
1>DemoApp.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::FontManager * QuickGUI::Singleton<class QuickGUI::FontManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VFontManager@QuickGUI@@@QuickGUI@@1PAVFontManager@2@A)
1>MainWindow.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::FontManager * QuickGUI::Singleton<class QuickGUI::FontManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VFontManager@QuickGUI@@@QuickGUI@@1PAVFontManager@2@A)
1>main.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::MessageManager * QuickGUI::Singleton<class QuickGUI::MessageManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VMessageManager@QuickGUI@@@QuickGUI@@1PAVMessageManager@2@A)
1>DemoApp.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::MessageManager * QuickGUI::Singleton<class QuickGUI::MessageManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VMessageManager@QuickGUI@@@QuickGUI@@1PAVMessageManager@2@A)
1>MainWindow.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::MessageManager * QuickGUI::Singleton<class QuickGUI::MessageManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VMessageManager@QuickGUI@@@QuickGUI@@1PAVMessageManager@2@A)
1>main.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::Log * QuickGUI::Singleton<class QuickGUI::Log>::ms_Singleton" (?ms_Singleton@?$Singleton@VLog@QuickGUI@@@QuickGUI@@1PAVLog@2@A)
1>DemoApp.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::Log * QuickGUI::Singleton<class QuickGUI::Log>::ms_Singleton" (?ms_Singleton@?$Singleton@VLog@QuickGUI@@@QuickGUI@@1PAVLog@2@A)
1>MainWindow.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::Log * QuickGUI::Singleton<class QuickGUI::Log>::ms_Singleton" (?ms_Singleton@?$Singleton@VLog@QuickGUI@@@QuickGUI@@1PAVLog@2@A)
1>main.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::SkinManager * QuickGUI::Singleton<class QuickGUI::SkinManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VSkinManager@QuickGUI@@@QuickGUI@@1PAVSkinManager@2@A)
1>DemoApp.obj : error LNK2019: unresolved external symbol "protected: static class QuickGUI::SkinManager * QuickGUI::Singleton<class QuickGUI::SkinManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VSkinManager@QuickGUI@@@QuickGUI@@1PAVSkinManager@2@A) referenced in function "public: __thiscall std::_Tree<class std::_Tmap_traits<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class QuickGUI::SkinElement *,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class QuickGUI::SkinElement *> >,0> >::_Tree<class std::_Tmap_traits<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class QuickGUI::SkinElement *,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class QuickGUI::SkinElement *> >,0> >(class std::_Tree<class std::_Tmap_traits<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class QuickGUI::SkinElement *,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class QuickGUI::SkinElement *> >,0> > const &)" (??0?$_Tree@V?$_Tmap_traits@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAVSkinElement@QuickGUI@@U?$less@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAVSkinElement@QuickGUI@@@std@@@2@$0A@@std@@@std@@QAE@ABV01@@Z)
1>MainWindow.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::SkinManager * QuickGUI::Singleton<class QuickGUI::SkinManager>::ms_Singleton" (?ms_Singleton@?$Singleton@VSkinManager@QuickGUI@@@QuickGUI@@1PAVSkinManager@2@A)
1>main.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::Core * QuickGUI::Singleton<class QuickGUI::Core>::ms_Singleton" (?ms_Singleton@?$Singleton@VCore@QuickGUI@@@QuickGUI@@1PAVCore@2@A)
1>DemoApp.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::Core * QuickGUI::Singleton<class QuickGUI::Core>::ms_Singleton" (?ms_Singleton@?$Singleton@VCore@QuickGUI@@@QuickGUI@@1PAVCore@2@A)
1>MainWindow.obj : error LNK2001: unresolved external symbol "protected: static class QuickGUI::Core * QuickGUI::Singleton<class QuickGUI::Core>::ms_Singleton" (?ms_Singleton@?$Singleton@VCore@QuickGUI@@@QuickGUI@@1PAVCore@2@A)
1>MainWindow.obj : error LNK2001: unresolved external symbol "public: static class QuickGUI::ColorValue const QuickGUI::ColorValue::Blue" (?Blue@ColorValue@QuickGUI@@2V12@B)
1>MainWindow.obj : error LNK2001: unresolved external symbol "public: static class QuickGUI::ColorValue const QuickGUI::ColorValue::Red" (?Red@ColorValue@QuickGUI@@2V12@B)
1>MainWindow.obj : error LNK2001: unresolved external symbol "public: static class QuickGUI::ColorValue const QuickGUI::ColorValue::White" (?White@ColorValue@QuickGUI@@2V12@B)
1>Scene.obj : error LNK2001: unresolved external symbol "public: static class QuickGUI::Position const QuickGUI::Position::ZERO" (?ZERO@Position@QuickGUI@@2V12@B)
1>C:\Ogre\QuickGUI_10_8\QuickGUIOgreDemo\\bin\QuickGUIOgreDemo.exe : fatal error LNK1120: 9 unresolved externals



I have linked the library QuickGUI.lib (I have compiled the 'QuickGUI.lib' without problem).
By cons I don't understand because in the info of the project there initially
QuickGUI_RelWithDebInfo.lib library (what is it ? ).
Thank you for your help

Are you using Visual Studio? Similar to Ogre, there is a "Release" build configuration, a "Debug" config, and a "RelWithDebInfo" configuration. I have only configured the "RelWithDebInfo" configuration, so any other configs may not work. The configuration is the same as building Ogre using Visual Studio.

Are you using Visual Studio? Similar to Ogre, there is a "Release" build configuration, a "Debug" config, and a "RelWithDebInfo" configuration. I have only configured the "RelWithDebInfo" configuration, so any other configs may not work. The configuration is the same as building Ogre using Visual Studio.
thank you for your reply.
I only use the element generated in Release. But I will study the problem more efore.