title: Django/Wagtail some images upload error 500
body: <p>Am using <a href="http://wagtail.io" rel="nofollow noreferrer">Wagtail</a> (Django variant CMS) in virtualenv, on FastCGI + Apache + shared hosting.</p>
  
  <p>When uploading images via the built-in Wagtail Image Uploader, certain images work and compile correctly whilst certain uploads cause a 500 Internal Server Error.</p>
  
  <p>Have tried looking for a pattern in types of images that cause the Error but can't spot any similarities. </p>
  
  <p>I am able to upload various JPGs, GIFs, PNGs, 
  sizes varied from 88KB to 236KB, 
  largest dimensions are 1000px x 950px</p>
  
  <p><img src="https://i.stack.imgur.com/y8sBH.png" alt="images uploaded"></p>
  
  <p>The files causing errors are also variety of JPGs, GIFs, PNGs. I cannot upload anything bigger than 300KB, although some files that are only 100KB or less also cause 500 error.
  Uploading via django-admin causes the same issues.</p>
  
  <p>The images work when I upload through sftp and cpanel so there's no problem there. </p>
  
  <p>Wagtail uses <code>Pillow</code> for image handling.</p>
  
  <p>I'm not sure where to begin looking for this. Is it a Pillow or Django error? </p>