QXcbClipboard: Unable to receive an event from the clipboard manager in a reasonable time

Ran into this while testing the 5.6.2 packages. I haven't been able to reproduce it consistently. The way I discovered it was by running the flat example, opening the menu on the side, then clicking on TextArea. Select some text in the TextArea, then close the application. It will take a while to close, and eventually you'll see the error message listed in the summary.