ddcui Frequently Asked Questions
See also the main ddcutil Frequently Asked Questions.
Console message qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow)
This warning message can occur when closing a dialog box, such as Feature Selection. It is a known bug in Qt, and will be fixed in an upcoming Qt release. (The fix has been applied to Qt 6.5.0 Beta1.) The message can be ignored.