Title: Caching problem / wp_cache_init() error / blank screen
Last modified: August 19, 2016

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# Caching problem / wp_cache_init() error / blank screen

 *  Resolved [Peter Kirn](https://wordpress.org/support/users/peterkirn/)
 * (@peterkirn)
 * [15 years, 4 months ago](https://wordpress.org/support/topic/caching-problem-wp_cache_init-error-blank-screen/)
 * Since upgrading to 3.0.4, I’ve had sporadic issues. Now, I can’t get the site
   to load at all – wp-admin, main page, nothing.
 * Server logs show wp_cache_init errors on each page load; e.g.,
    2011/01/03 01:
   02:40 [error] 13253#0: *1757 FastCGI sent in stderr: “PHP Fatal error: Call to
   undefined function wp_cache_init() in /home/noise/wp-includes/load.php on line
   378” while reading response header from upstream, client: 82.242.74.54, server:
   noisepages.com, request: “GET / HTTP/1.1”, upstream: “fastcgi://unix:/dev/shm/
   php-fastcgi.sock:”, host: “createdigitalmotion.com”, referrer: “[http://www.google.com/reader/view/&#8221](http://www.google.com/reader/view/&#8221);
 * I’m running nginx + APC.
 * I have tried disabling the MySQL query cache and APC caching temporarily to see
   if those were somehow conflicting (based on previous comments) — nothing.
 * Also, I tried doing a clean install of WP in a separate directory and switching
   to that. That fixed everything — for about fifteen minutes, and then the problem
   resurfaced (which *really* says to me there’s a caching problem!)
 * I would think that disabling the WP cache would resolve the issue, right? Shouldn’t
   I be able to choose —
 * define(‘WP_CACHE’, false);
 * — in wp-config.php?

Viewing 4 replies - 1 through 4 (of 4 total)

 *  Thread Starter [Peter Kirn](https://wordpress.org/support/users/peterkirn/)
 * (@peterkirn)
 * [15 years, 4 months ago](https://wordpress.org/support/topic/caching-problem-wp_cache_init-error-blank-screen/#post-1842050)
 * FYI, to avoid conflicts, I have temporarily disabled both MySQL query cache (
   my.cnf — set query cache size to 0) and APC (disabled the module in php.ini)…
 * So that still seems to me that it’s WP’s internal cache; why else would I be 
   getting wp_cache_init() called at all?
 *  Thread Starter [Peter Kirn](https://wordpress.org/support/users/peterkirn/)
 * (@peterkirn)
 * [15 years, 4 months ago](https://wordpress.org/support/topic/caching-problem-wp_cache_init-error-blank-screen/#post-1842054)
 * Correction —
    Restarting php-fpm appears to, at least temporarily, correct the
   problem. I think maybe my APC setting didn’t conflict before?
 * I’ve seen APC issues boil down to one or two lines of code. Is there a simple
   diff WP devs maintain for 3.0.4 so I can see if I can track down a change that
   could possibly have triggered (or worsened the symptoms of) one of these APC 
   wrinkles? I know WP users have been bitten by APC before(!)
 *  Thread Starter [Peter Kirn](https://wordpress.org/support/users/peterkirn/)
 * (@peterkirn)
 * [15 years, 4 months ago](https://wordpress.org/support/topic/caching-problem-wp_cache_init-error-blank-screen/#post-1842203)
 * I can confirm that the older version of APC, 3.0.16, can cause this issue. It
   appears that it either surfaced out of the blue or, more likely, as a result 
   of a change to a file in the WP 3.0.4 upgrade. I consider the issue resolved,
   but will investigate what specific change may have cause the problem and if the
   newer build of APC is compatible.
 *  Thread Starter [Peter Kirn](https://wordpress.org/support/users/peterkirn/)
 * (@peterkirn)
 * [15 years, 4 months ago](https://wordpress.org/support/topic/caching-problem-wp_cache_init-error-blank-screen/#post-1842204)
 * For anyone having the issue, additional notes that may be useful:
    1. Look for
   apc.php, and move it to a web-served directory, in order to check the active 
   version (and other helpful info). 2. You’ll find the apc enable flag in php.ini
   to disable it. 3. If you’re using php-fpm as I am, you need to restart the php-
   fpm daemon in order for the module to fully deactivate. (easy to forget to do!)
 * It seems that other people are having issues with APC not fully updating.

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘Caching problem / wp_cache_init() error / blank screen’ is closed to 
new replies.

## Tags

 * [caching](https://wordpress.org/support/topic-tag/caching/)
 * [errors](https://wordpress.org/support/topic-tag/errors/)
 * [installation](https://wordpress.org/support/topic-tag/installation/)
 * [servers](https://wordpress.org/support/topic-tag/servers/)
 * [WP_CACHE](https://wordpress.org/support/topic-tag/wp_cache/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 4 replies
 * 1 participant
 * Last reply from: [Peter Kirn](https://wordpress.org/support/users/peterkirn/)
 * Last activity: [15 years, 4 months ago](https://wordpress.org/support/topic/caching-problem-wp_cache_init-error-blank-screen/#post-1842204)
 * Status: resolved

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