Crash when saving ofXml on exit() callback

On VisualStudio 2015 WIN 10 here;

A simple ofApp that tries to save an ofXml on exit() crashes somewhere in boost;

Unhandled exception thrown: read access violation.
this->_Ptr->_Facetvec was 0x111011101110111.

    BaseApp_debug.exe!std::locale::_Getfacet(unsigned __int64 _Id) Line 459 C++
    BaseApp_debug.exe!std::use_facet<std::codecvt<wchar_t,char,_Mbstatet> >(const std::locale & _Loc) Line 564  C++
    BaseApp_debug.exe!boost::filesystem::path::codecvt() Line 904   C++
    BaseApp_debug.exe!boost::filesystem::path_traits::convert(const char * from, const char * from_end, std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t> > & to) Line 837    C++
    BaseApp_debug.exe!boost::filesystem::path_traits::dispatch<std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t> > >(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & c, std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t> > & to) Line 256 C++
    BaseApp_debug.exe!boost::filesystem::path::path<char [9]>(const char[9] & source, void * __formal) Line 140 C++
    BaseApp_debug.exe!ofApp::exit() Line 15 C++
    BaseApp_debug.exe!ofBaseApp::exit(ofEventArgs & args) Line 72   C++
    BaseApp_debug.exe!ofEvent<ofEventArgs,std::recursive_mutex>::make_function::__l2::<lambda>(const void * __formal, ofEventArgs & t) Line 440 C++
    [External Code] 
    BaseApp_debug.exe!of::priv::Function<ofEventArgs,std::recursive_mutex>::notify(const void * s, ofEventArgs & t) Line 90 C++
    BaseApp_debug.exe!ofEvent<ofEventArgs,std::recursive_mutex>::notify(const void * sender, ofEventArgs & param) Line 524  C++
    BaseApp_debug.exe!ofNotifyEvent<ofEvent<ofEventArgs,std::recursive_mutex>,ofEventArgs,ofMainLoop>(ofEvent<ofEventArgs,std::recursive_mutex> & event, ofEventArgs & args, ofMainLoop * sender) Line 210  C++
    BaseApp_debug.exe!ofMainLoop::exit() Line 169   C++
    BaseApp_debug.exe!ofExitCallback() Line 235 C++

The code is super simple:

class ofApp : public ofBaseApp{
    public:
    void exit() {
        ofXml s;
        s.save("test.xml");
    }
}

Saving the xml is totally fine when I attempt to do it while the app is running; so it must be something related to the exit() call;

Reproduce the crash on Visual Studio 2015 and Windows 10 with the shown ofApp::exit() example. Trace ofXml::save() through ofBaseApp::exit() and ofMainLoop::exit(), using the reported Boost filesystem and locale stack as the starting point. Done means saving test.xml from exit() no longer crashes while saving during normal runtime still works.