title: Cakephp image -Can not determine the mimetype
body: <p>cakephp 2.3</p>
  
  <p>I'm uploading an image and I have an error saying that:</p>
  
  <pre><code>Can not determine the mimetype.
  
  Error: An Internal Error Has Occurred.
  </code></pre>
  
  <p>On my Model this is a part of my $validation</p>
  
  <pre><code>'file_name' =&gt; array(
              'uploadError' =&gt; array(
                  'rule' =&gt;'uploadError',
                  'message' =&gt; 'Your image upload failed',
                  'allowEmpty' =&gt; FALSE,
                  //'required' =&gt; false,
                  //'last' =&gt; false, // Stop validation after this rule
                  //'on' =&gt; 'create', // Limit validation to 'create' or 'update' operations
              ),
              'mimeType' =&gt; array(
                  'rule' =&gt; array('mimeType', array('image/gif', 'image/png', 'image/jpg', 'image/jpeg')),
                  'message' =&gt; 'Please only upload images (gif, png, jpg).',
                  'allowEmpty' =&gt; FALSE,
                  ),
              'fileSize' =&gt; array(
                  'rule' =&gt; array('fileSize', '&lt;=', '2MB'),
                  'message' =&gt; 'Your image must be less than 2MB or(2048ko).',
                  'allowEmpty' =&gt; FALSE,
                  ),
              'processCoverUpload' =&gt; array(
                  'rule' =&gt; 'processCoverUpload',
                  'message' =&gt; 'Unable to process cover image upload.',
                  'allowEmpty' =&gt; FALSE,
                  ),
              'unique' =&gt; array(
                  'rule' =&gt; 'isUnique',
                  'message' =&gt; 'This file name is already exist in your folder',
                  'required' =&gt; 'create',
                  'allowEmpty' =&gt; FALSE,
                  ),
          ),
  </code></pre>
  
  <p>I'm only allow 3 types of mimetype. any help?</p>