Title: Segmentation fault when enabling Optimize CSS Code
Last modified: August 31, 2016

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# Segmentation fault when enabling Optimize CSS Code

 *  Resolved [ryangcad](https://wordpress.org/support/users/ryangcad/)
 * (@ryangcad)
 * [10 years ago](https://wordpress.org/support/topic/segmentation-fault-when-enabling-optimize-css-code/)
 * I just installed this plugin on my local test box and when I enable the optimize
   CSS Code, I am getting an internal server 500 error. I checked through the Support
   page and confirmed I had my AllowOverride All.
    I installed the plugin on my 
   staging site Remote Host) and got the same thing when enabling Optimize CSS. 
   Checked the Apache logs on my local server and found that when I enable it, I
   get [core:notice] [pid:xxxx] AH00051: child pid xxxx exit signal Segmentation
   Fault (11). My local PHP version is 5.5.9-1. Zend engine 2.5.0 Zend OPcache 7.0.3.
   These should be pretty close to the latest version. My WP site is 4.4.3. I am
   using WooCommerce and Divi and I don’t have any other optimization plugins installed.
   Again, if I just disable Optimize CSS everything works again.
 * [https://wordpress.org/plugins/autoptimize/](https://wordpress.org/plugins/autoptimize/)

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Author [Frank Goossens](https://wordpress.org/support/users/futtta/)
 * (@futtta)
 * [10 years ago](https://wordpress.org/support/topic/segmentation-fault-when-enabling-optimize-css-code/#post-7415946)
 * Hi ryangcad;
    That’s PCRE (perl compatible regular expressions) crashing PHP,
   probably due to the the amount of CSS OR due to something … funky in the CSS.
   As per [the FAQ](https://wordpress.org/plugins/autoptimize/faq/);
 * > In some rare cases [the CSS minification component currently used by Autoptimize](https://github.com/tubalmartin/YUI-CSS-compressor-PHP-port/)
   > crashes due to a lack of resources ([see detailed technical explanation here](http://blog.futtta.be/2014/01/14/irregular-expressions-have-your-stack-for-lunch/)).
   > You can in that case either disable CSS optimization, try to exclude specific
   > CSS from being aggregated or activate the legacy minifiers which don’t have
   > that problem. The latter can be accomplished by adding this to your wp-config.
   > php:
   > `define("AUTOPTIMIZE_LEGACY_MINIFIERS","true");`
   > The “legacy minifiers” will remain in Autoptimize “for ever” and changes to
   > wp-config.php are not affected by core-, theme- or plugin-upgrades so you should
   > be good to go.
 * If that does not work, you can try selectively excluding one or more CSS-files
   from optimization.
 * hope this helps,
    frank
 *  Thread Starter [ryangcad](https://wordpress.org/support/users/ryangcad/)
 * (@ryangcad)
 * [10 years ago](https://wordpress.org/support/topic/segmentation-fault-when-enabling-optimize-css-code/#post-7416024)
 * Thanks so much for the reply. I added the legacy minifyers and that seems to 
   have corrected the issue.
    One thing that is interesting is that I have tried
   to minify my style.css files in the past for my theme and have always had formatting
   issues but when doing it through Autoptimize, it is working great.

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Segmentation fault when enabling Optimize CSS Code’ is closed to new 
replies.

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## Tags

 * [apache2](https://wordpress.org/support/topic-tag/apache2/)

 * 2 replies
 * 2 participants
 * Last reply from: [ryangcad](https://wordpress.org/support/users/ryangcad/)
 * Last activity: [10 years ago](https://wordpress.org/support/topic/segmentation-fault-when-enabling-optimize-css-code/#post-7416024)
 * Status: resolved