Cannot add components to MCU project.

I am starting from a fresh Qt install as I thought that would fix this, but when I create a new Qt for MCUs project, and then add a UI form class to the project, I cannot add any components to the UI, and get an error when I try to view in design view. When I click the '+' button to expand the component selection, nothing happens. I do not have this issue when building a standard Qt Quick/QML project, only when I create a Qt for MCUs project. I had created a bug report for this under Qt for MCUs, but they verified it is not a Qt for MCUs bug (https://bugreports.qt.io/browse/QTMCU-62).