Title: Call to undefined function mb_detect_encoding()
Last modified: January 18, 2020

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# Call to undefined function mb_detect_encoding()

 *  Resolved [Zelon](https://wordpress.org/support/users/zelon/)
 * (@zelon)
 * [6 years, 4 months ago](https://wordpress.org/support/topic/call-to-undefined-function-mb_detect_encoding-3/)
 * Hello,
 * I recently updated plugins and found that my WordPress site would no longer function,
   throwing up a PHP error…..
 *     ```
       Call to undefined function mb_detect_encoding()
       ```
   
 * This would appear to indicate that Merge-Minify-Refresh started using the mbstring
   PHP extension in a recent update. This is not included in a default PHP installation,
   so it might take some users by surprise.
 * To fix this problem I simply installed the PHP mbstring extension for my PHP 
   version and then restarted apache.
 *     ```
       sudo apt-get install php7.2-mbstring
       sudo service apache2 restart
       ```
   

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

 *  Thread Starter [Zelon](https://wordpress.org/support/users/zelon/)
 * (@zelon)
 * [6 years, 4 months ago](https://wordpress.org/support/topic/call-to-undefined-function-mb_detect_encoding-3/#post-12342096)
 * Marked as resolved because this was more of an informational post anyway. Good
   luck fellow WordPress-ers!
 *  Plugin Author [launchinteractive](https://wordpress.org/support/users/launchinteractive/)
 * (@launchinteractive)
 * [6 years, 4 months ago](https://wordpress.org/support/topic/call-to-undefined-function-mb_detect_encoding-3/#post-12342283)
 * Thanks for posting this [@zelon](https://wordpress.org/support/users/zelon/)
   
   I’ve just pushed out a new version of MMR that now checks for the existence of
   mbstring. If mbstring isn’t installed MMR should still work fine unless a JS 
   or CSS file is encoded in ISO-8859-1.

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

The topic ‘Call to undefined function mb_detect_encoding()’ is closed to new replies.

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## Tags

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

 * 2 replies
 * 2 participants
 * Last reply from: [launchinteractive](https://wordpress.org/support/users/launchinteractive/)
 * Last activity: [6 years, 4 months ago](https://wordpress.org/support/topic/call-to-undefined-function-mb_detect_encoding-3/#post-12342283)
 * Status: resolved