Ever have an issue where you're trying to place a back panel on a top and it seems that the panel wants to place on the wrong side of the surface?
There is an easy solution. Simply click on the "Select Single Object" button, and then click on the top that you are having issue with. Rotate that top to the correct orientation, and it will be fixed. In our example our top needed to rotate to the 0 degree angle.
Now the back panel can be placed correctly.