One of the vendors allows for payment by credit card. Under the PAY BILLS tab I selected credit card with the account Capital One. I then realized I wanted to write a check, but the bill is nowhere to be found so it can be change to write a check.
It sounds like you have already paid the bill with the credit card. If that is the case go to your credit card register and delete the payment. This will put the bill back into your accounts payable screen whereby allowing you to pay by check.