setting scrollable causes container to vanish

[kencl]

Weird problem here. When I set the scrollable property on a container, it's contents vanish! Please see the screencaps to see what I mean. The only purpose for that container is to make that long list of checkboxes scrollable.

Any ideas what's wrong here?

[aconran]

If you want to make it scrollable, you'll need to give it a height.

[kencl]

I guess it's hard to see because this forum reduces the image size, but the height was already set at 100%

[aconran]

Give it a fixed number. If you are looking for it to stretch to fit the rest of the available space, use a vbox layout and set an appropriate flex value.