Can't delete measures in MS3

Upgraded from MS2 to MS3 yesterday. I have finished a piece that has extra bars at the end. In MS2 this was a simple matter of selecting the excess bars and selecting "delete selected measures" from the dropdown menu. However, when I do the same thing in MS3 nothing happens. The unwanted excess bars remain and cannot be deleted. Thoughts? Of course, I could cut and paste the piece into a fresh file that has the correct number of bars from the outset, but that seems a lot of unnecessary work.