When using the Civils Extension and have projected the locations in to a drawing you may find that when you click an option on the ribbon nothing seems to happen but also there is no "Failed to load" message on the command line.
The cause of this is most likely the option you clicked is off screen. This could be on another monitor or worse not on any screen.
To fix this issue you will need to reset the AutoCAD UI options back to default.
Go to Start>**AutoCAD Civils version** and select "Reset Settings to Default"
Follow the steps and then try the extension again.