over defined

I am new to solid works and trying to draw some sheet metal part from the tutorial, but am finding that i keep getting the message "over defined". But how do I know hich part of the dwg needs to be adjusted to solve this?

Solids fail, that's what they do.

All those things that you have been picking while building your model, Solidworks is remembering. If something is removed then this causes an error. These errors can quickly be resolved by looking at the feature manager tree and looking for indicators which is covered in the online manual. You have to learn these.

In an overdefined situation, typically a sketch will give you an indicator or an assembly will show you an error. The easiest way to fix these errors is to remove one constraint at a time til you understand why it's busted. In the future there's some technology that solidworks is developing that will help solve over defined designs.

All I have drawn is a U shape sheet metal part from the online tutorial, I then added a tab one side then put a line across where the tab is to be folded. This is the point where the problem occurs I dimension the height from new scribed bend line to the top of the tab also dimension the bend line (although I don't think I need to) All looks ok but then I click on sketched bend, this then gives the notice that the dwg requires a fully defined dwg. Ikeep following the online tutorial word for word and still get stuck each time at this point. Really frustrated any further advice would be greatly apreciated. (using 2003 version with the tutorial ).