Title: getting a warning
Last modified: September 1, 2016

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# getting a warning

 *  Resolved [vragour](https://wordpress.org/support/users/vragour/)
 * (@vragour)
 * [9 years, 10 months ago](https://wordpress.org/support/topic/getting-a-warning-2/)
 * Getting this warning over all om my page
 * _Warning: Parameter 1 to W3\_Plugin\_TotalCache::ob\_callback() expected to be
   a reference, value given in /customers/e/b/8/skovbjerg-strik.dk/httpd.www/wp-
   includes/functions.php on line 3549_
 * [https://wordpress.org/plugins/w3-total-cache/](https://wordpress.org/plugins/w3-total-cache/)

Viewing 3 replies - 1 through 3 (of 3 total)

 *  [Ashok](https://wordpress.org/support/users/bappidgreat/)
 * (@bappidgreat)
 * [9 years, 10 months ago](https://wordpress.org/support/topic/getting-a-warning-2/#post-7564912)
 * Hello vragour
 * Please go to /wp-content/plugins/w3-total-cache/lib/W3/Plugin/TotalCache.php 
   line no 512 and replace:
 *     ```
       function ob_callback(&$buffer) {
       ```
   
 * with
 *     ```
       function ob_callback($buffer) {
       ```
   
 * Let us know if this works well.
 * Have a good day!
 * Cheers
    Ash
 *  Thread Starter [vragour](https://wordpress.org/support/users/vragour/)
 * (@vragour)
 * [9 years, 10 months ago](https://wordpress.org/support/topic/getting-a-warning-2/#post-7564932)
 * hey Ashok
    Thank you for your help it fix it 🙂 Cheers vgraour
 *  [responsivemenu](https://wordpress.org/support/users/responsivemenu/)
 * (@responsivemenu)
 * [9 years, 10 months ago](https://wordpress.org/support/topic/getting-a-warning-2/#post-7565031)
 * Hi there,
 * I have the same issue here.
 * Although this works, this involves editing the core files which means I will 
   have to do this on every plugin update.
 * Can the author step in and advise why this is happening and if it will be fixed
   in a future version?
 * Only difference with my sites that do work is that I am running PHP 7 with Fast
   CGI if that makes any difference.
 * All the best

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘getting a warning’ is closed to new replies.

 * ![](https://ps.w.org/w3-total-cache/assets/icon-256x256.png?rev=1041806)
 * [W3 Total Cache](https://wordpress.org/plugins/w3-total-cache/)
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 * [Support Threads](https://wordpress.org/support/plugin/w3-total-cache/)
 * [Active Topics](https://wordpress.org/support/plugin/w3-total-cache/active/)
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## Tags

 * [warning](https://wordpress.org/support/topic-tag/warning/)

 * 3 replies
 * 3 participants
 * Last reply from: [responsivemenu](https://wordpress.org/support/users/responsivemenu/)
 * Last activity: [9 years, 10 months ago](https://wordpress.org/support/topic/getting-a-warning-2/#post-7565031)
 * Status: resolved