title: Uploading screenshots error to the developer console
body: <p>I get the following error when trying to upload an image as a screenshot to my developer console:</p>
  
  <p>"You need to check that your screenshot image is a valid image."</p>
  
  <ol>
  <li>I took a screenshot from my cell and uploaded it as a screenshot to the developer console and it worked.</li>
  <li>Then I just added a line on top of the image using paint.</li>
  <li>Tried to upload the modified image to the developer console but it failed.</li>
  </ol>
  
  <p>My images are480wx800h PNG formatted images so it should be okay. (both the original and the modified bitmap).</p>
  
  <p>Could any1 tell me how to solve this?
  I want to upload a sample image from my app and add some instructions written on top of the image. 
  But i can't do it.</p>