When Layout Assistant is launched, ElumTools parses all the geometry for the selected calculation areas and performs a basic radiosity calculation to use in the Layout Assistant estimation process. For complex environments, this can be a slow process, and the Layout Assistant dialog will appear blank in the interim. This behavior is normal does not indicate a problem.
Users with a Network License should refrain from clicking any of the ElumTools icons on the Windows Task Bar while waiting for Layout Assistant to load. Doing so triggers an interesting bug that causes the program to think it's license has been lost, resulting in the error below.
This bug will be fixed in the next ElumTools update.