Problems subclassing QListWidgetItem

[Morea]

The problem went away when I removed Q_OBJECT from the code.

[wysota]

Q_OBJECT provides some additional functionality for objects -- like signals, slots, etc. But it also requires that the class inherits QObject, which was missing in your case. But if you don't need signals/slots or meta-data, you don't need the Q_OBJECT macro.