Dont need more, i have solved.
But u can try it:
wstring test;
test = L"coração"; // <-error
sf::String textBox;
sf::Font font;
if (!font.LoadFromFile("dados\\fontes\\tahoma.ttf"))
{
//failed
}
textBox.SetText(test);
textBox.SetSize(12);
textBox.SetFont(font);
Conclusion, you can put in WSTRING some portuguese letters, or if you force with cast, occur the same problem.
Solution: use only STRING on SetText.