Vectorworks 2015 SP5 and OS X 10.11 El Capitan

Service Pack 5 for Vectorworks 2015, available from THIS LOCATION  addresses the majority of the compatibility issues introduced since OS X 10.10, however there is a particular UI element that you may come across that can be worked around:
 

After switching focus from Vectorworks 2015 to another application on OS X 10.11, you may notice that any dialog boxes (Such as Tools > Organization) may not reappear after switching focus back to Vectorworks 2015, either via the use of Spaces or by using CMD+Tab. To force these dialogs to reappear, all you need do is switch your focus to the Desktop, normally via Expose, click on a blank area of the desktop, then click back on the Vectorworks 2015 icon in the Dock.