User has embed a window from a Java based application into QWidget based application into a QStackedWidget using:

m_tbkWidget = QWidget::createWindowContainer(QWindow::fromWinId(iface>windowHandle()));
m_stackedWidget->addWidget(m_tbkWidget);

This worked for him for many years.

Now with only known difference compiler updates, switching the active widget in the QStackedWidget from the windowContainer to a standard QWidget the QLineInputs show the cursor if clicked, but don't accept keyboard inputs any more.

Support has tested customers test case and could not write to the field.

Test case project has been attached.

Steps to reproduce the issue:

• Start the application (there is a sleep(2) to give the editor time to start up)
• Type something in the editor on the right
• Click button 2
• Try to type something in the line edit (does not work for me)
• Click right mouse button in QLineEdit
• Try to type again (works now after the popup was shown

Workaround has been to add:

lineEditWidget->activateWindow();