How do I make the "Remove Part" warning/error go away?

I am writing a competitive price analysis and received a warning to "Remove Part". How do I make this error go away?

As the warning states, you must have two or more valid bids in order for competition to be adequate. This error appears when you have only entered information for one bidder.

To remove the error:

1. Click the Green +Add Bidder button.

2. Add the information for your next bidder(s).