Sorry, not even close--what i am trying to do here is make a hole in the rectangle thingee by putting a cylinder in it, choosing the Boolean Modifier 'Difference', and applying. Problem is, i get that error message when i click on apply. I tried a google search with that exact phrase and came up with a lot of stuff, but nothing worked for me. I would appreciate it if someone who knows about this will point out what i am doing wrong.
I am sure there are other ways of cutting out a hole, but i would very much prefer to have my Modifier working.