NextButton not clicked in CredentialsPageCallback

This:

Controller.prototype.CredentialsPageCallback = function()

{ var widget = gui.currentPageWidget(); var username = installer.environmentVariable("QT_ACCOUNT_USERNAME"); var password = installer.environmentVariable("QT_ACCOUNT_PASSWORD"); widget.loginWidget.EmailLineEdit.setText(username); widget.loginWidget.PasswordLineEdit.setText(password); gui.clickButton(buttons.NextButton); }

worked in 3.2.3, but not in 4.1.1. The next button is never clicked. The installer pauses and waits for the next button to be clicked.