WordPress, Images and 550.50 IIS errors

iconI am using WordPress on Windows IIS. I am uploading images in WordPress for a blog post. The image displays fine on the web site but as soon as I enable permalinks the images no longer work and any future images uploaded I get back an error:

HTTP Error 500.50 - URL Rewrite Module Error.
The page cannot be displayed because an internal server error has occurred.

Here is my web.config created by WordPress:

<?xml version="1.0" encoding="UTF-8"?>
        <rule name="wordpress" patternSyntax="Wildcard">
          <match url="*" />
              <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
              <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
          <action type="Rewrite" url="index.php" />

As soon as I turn off my permalinks and use the default it works, does anyone know why this could be?


The image issue was a permission issue, but simply setting it manually on the original image file or parent folder is inadequate. The behavior of WordPress is that it writes the original file using IUSR to a temporary system directory that is defined in the PHP.ini file. This temp folder does not have IIS_IUSRS permissions on it, so when windows moves this file from the temp folder to the application’s upload folder, its final home, IIS_IUSRS only has read permissions, so the permissions are not inherited from the file’s parent folder.

To fix this, there are two solutions:

  • Change the permissions on the temp folder giving IIS_IUSRS write/modify.
  • Change the path of the temp folder in the PHP.ini file to a folder that does have IIS_IUSRS write/modify permission.

Here is a good source detailing the problem, plus the original answer on stackoverflow.

After this change and uploading an image in wp-admin, I was able to access the image (original, not resized) from a browser without the 500.50 error.