Ok, I'm trying to follow a tutorial and I'm stuck at this one part. Here is an excerpt from the tutorial,

"With the square (MonitorProfileShape01) selected, Go to the Maya Outliner (you can select it in your viewport by selecting the Persp/Outliner Tab on the Left side Toolbar. You will see a List of all objects in your scene.

In the Outliner Press the (-) minus sign next to MonitorProfileShape01. You will see each side listed. Select the fist 2 sides and open the *Edit Curves*Attach Curves › Options Window. Set Attach Method to Blend and hit Apply. (leave the window open you will be using it again. Now select the first and third sides and repeat Attach Command. Next, select the first and fourth sides and repeat again (now you can close the › Options Window).

Finally, with the entire square selected, open the *Edit Curves*Open/Close Curve › Options Window. Set the Shape to Blend and hit Open/Close. You now have a square that is a Periodical Curve with no overlapping CV's."

Now I do that exactly but when I use the edit Curves Open/Close Curve I get an error message - Curve 3 invalid or something like that and my object either disapears or does nothing what it is supposed to do, it is supposed to round the corners of the object
HELP!!

THanks guys