1. Make sure you are typing the name of the script exactly. MEL is case-sensitive. Also, make sure you followed the directions in the MEL script exactly (just open up the .mel file in any text editor and look at the top of the script). Finally, if you installed the script while Maya was running, either restart Maya or source the script.

2. You may have accidentally turned on Scale Snapping. You can turn it off by unchecking "Discrete Scale" in the scale tool options dialog (double-click Scale tool) or by selecting "Snap Scale" from the scale marking menu (hold down "r" and left-click to bring up the marking menu).

3. Open up Outliner (Window > Outliner). In the list of objects, hidden objects are displayed in blue text. Select the ones you want to make visible and go to Display > Show > Show Selection.

4. You can set any of the view panels to be your Render Panel. In the view panel menu, select Panels > Panel > Render View.