Issue Description
Balusters cannot be created for the railing in the pattern editor.
Solution
To add a baluster, choose the header from the left-hand panel, then click the plus button located at the top right. Your mouse pointer will change to a pen symbol; click once in the white space.
If you're still unable to add them, let's review the settings for railing selection > Railing > Segment > Panels. If a panel is already active or added, it must be removed using the "-" button at the top right before adding the balusters.
TIP: How to create a custom Rail