Unsolved QString Error

[sad2]

Actually i'm using Qt 5.9 but this error appears when i try run my code:

The QString library are declared, i dont know what to do, someone can help me?

[Eddy]

Hi sad2 ,

what OS are you using?

[AlexMal]

how commando_ant is declared?
By the way fromAscii is obsolete you can use fromLatin1() instead.
It still should be available though.

[Eddy]

from the qstring.h sources :

#if QT_DEPRECATED_SINCE(5, 0)
    QT_DEPRECATED static inline QString fromAscii(const char *str, int size = -1)
    { return fromLatin1(str, size); }
    QT_DEPRECATED static inline QString fromAscii(const QByteArray &str)
    { return fromLatin1(str); }
    Q_REQUIRED_RESULT QByteArray toAscii() const
    { return toLatin1(); }
#endif

So obviously it is in there but, you have to change some settings in your app. I would follow @AlexMal 's advice however.