title: Paypal Error #10602 in Magento
body: <p>When I first set up Paypal in Magento I had the transaction processing mode set to "authorize". One order was processed with this mode then. </p>
  
  <p>Now I cannot manage to set this first order to "complete". The status stays in "processing". Instead I am getting below error when I want to alter this order or invoice on the product;</p>
  
  <pre><code>PayPal gateway has rejected request. Authorization has already been completed (#10602: Authorization completed).
  </code></pre>
  
  <p>The Paypal transaction is authorized and completed. I have changed the transaction processing mode to "sale" now and I am not getting any errors for new orders anymore but I have still the error on the first order and the status is still "processing", </p>
  
  <p>However I want that to be changed to "complete" and finally close the order.
  Any ideas how to do it in an easy way?</p>