Answers.Body: <p>You're likely missing the PHP <a href="https://php.net/manual/en/book.json.php" rel="nofollow">JSON extension</a>, which is a <a href="http://buildwithcraft.com/docs/requirements#required-php-extensions" rel="nofollow">requirement</a> to run Craft.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-26T20:18:57.723Z
Answers.LastActivityDate: 2015-04-26T20:18:57.723Z
Answers.UserDisplayName: Brad Bell
Body: <p>I'm running PHP 5.3.3, which the docs say is supported, but if I try to go to the main admin page or go to add a field, I'm getting an error: 
      Use of undefined constant JSON_HEX_TAG - assumed 'JSON_HEX_TAG'</p>
  
  <p>Everything I'm finding online points to this being an outdated PHP issue, but thought I would check since I am running a supported version of PHP. </p>
  
  <p>Thanks!</p>
  
Tags: <error-message><php><json>
Title: Use of undefined constant JSON_HEX_TAG
ThreadText: # Use of undefined constant JSON_HEX_TAG
  
  (Asked by: username_0 on 2015-04-26)
  
  I'm running PHP 5.3.3, which the docs say is supported, but if I try to go to the main admin page or go to add a field, I'm getting an error:
  Use of undefined constant JSON\_HEX\_TAG - assumed 'JSON\_HEX\_TAG'
  
  Everything I'm finding online points to this being an outdated PHP issue, but thought I would check since I am running a supported version of PHP.
  
  Thanks!
  
  **Tags:** error-message, php, json
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2015-04-26. Score: 4 | Accepted answer
  
  You're likely missing the PHP [JSON extension](https://php.net/manual/en/book.json.php), which is a [requirement](http://buildwithcraft.com/docs/requirements#required-php-extensions) to run Craft.
  
  
  ---
  
  