Yes, that happened to me, and I was new to quilting. Luckily, it was a pieced quilt so I could just add more of the background fabric outside the design to make the blocks the right size. I agree that patterns should be tested before they are shared or sold.
I just made a mug rug and didn't scroll far enough down -- at the bottom was a link that stated it was for options and pattern corrections. I think if it was my web site I would just put the corrections in the pattern. Easier to change than a printed book!