Hello, everyone! I have already answred here: http://lists.boost.org/boost-users/2012/07/75097.php But previous latter badly typed. When using boost::locale with the russian language of the string in UTF-8 encoding I get an error while getting the locale. An exception with the message e.what(): "Conversion failed" is thrown My code is not very different from that in the examples: #define TR(S) boost::locale::translate(S).str() const std::string strDefaultLangId( "en" ); int main( int argc, char * argv[] ) { using namespace std; using namespace boost::locale; int exitCode = EXIT_SUCCESS; try { generator gen; gen.add_messages_path("g:\\source\\boost_locale\\languages\\"); gen.add_messages_domain("messages"); std::string language( argc == 2 ? argv[1] : strDefaultLangId.c_str() ); std::locale loc = gen( language ); locale::global( loc ); std::wstring s = TR(L"hello world"); wcout << s << endl; } catch( exception& e ) { cout << "Error : " << e.what() << endl; exitCode = EXIT_FAILURE; } catch( ... ) { cout << "Unknown error" << endl; exitCode = EXIT_FAILURE; } return exitCode; } The path to the file with the russian language: "g:\source\boost_locale\languages\ru\LC_MESSAGES\messages.mo" What could be wrong? * Is it necessary to use the backends? * Is it yet necessary to call imbue on the stream? But I'd like avoid it because I am going to write the log using glog. Compillers : Microsoft Visual Studio 2008 and 2010 Boost version : 1.49