Found this :https://wiki.qt.io/Transition_from_Qt_4.x_to_Qt5
about this issue.
This gets raised, when trying to use compiled widget (pyside-uic....), which has the retranslateUi() .
QApplication::translate("Href_Gui", "Text:", 0, QApplication::UnicodeUTF8)
QApplication::translate("Href_Gui", "Text:", 0)
Not really sure how to tackle this down.