Can't Apply Layout to a GroupBox in Qt Creator

[osssome]

Hi,

When I drop a new GroupBox onto the CentralWidget, it puts the GroupBox just fine, but the QGroupBox icon has a red line through it and it has no Layout property section. GroupBoxes are supposed to be able to have a built-in (not a child) Layout property section that lets me resize the GroupBox, and I don't know how.

Thanks

Qt Creator 3.4.2 based on Qt 5.5.0