Title: Undefined index: mbstring…
Last modified: April 16, 2022

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# Undefined index: mbstring…

 *  Resolved [Ambyomoron](https://wordpress.org/support/users/josiah-s-carberry/)
 * (@josiah-s-carberry)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/undefined-index-mbstring/)
 * With the upgrade to ver. 4.2.22 on WP 5.9.3 the following message is now displayed
   twice when any site page is loaded:
 * `Notice: Undefined index: mbstring in /blahblah/wp-content/plugins/webba-booking-
   lite/vendor/voku/portable-utf8/src/voku/helper/UTF8.php on line 5368`

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

 *  Plugin Author [Webba Appointment Booking](https://wordpress.org/support/users/webba-agency/)
 * (@webba-agency)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/undefined-index-mbstring/#post-15565145)
 * Hello,
 * It seems debug mode is enabled in your WordPress.
 * Please, disable it by updating the file wp-config.php:
 * `define('WP_DEBUG', false);`
 * If the problem persist, please let me know.
 *  Thread Starter [Ambyomoron](https://wordpress.org/support/users/josiah-s-carberry/)
 * (@josiah-s-carberry)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/undefined-index-mbstring/#post-15565844)
 * That is correct. The message disappears when debugging is disabled.
    It is hard
   to understand, though, why debugging result in this, and only this, message.
 *  Plugin Author [Webba Appointment Booking](https://wordpress.org/support/users/webba-agency/)
 * (@webba-agency)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/undefined-index-mbstring/#post-15566603)
 * Hello,
 * Could you please forward your debug.log file from the wp-content folder to [support@webba-booking.com](https://wordpress.org/support/topic/undefined-index-mbstring/support@webba-booking.com?output_format=md)?
   For a better follow-up, please drop a line here after sending an email.
 *  Thread Starter [Ambyomoron](https://wordpress.org/support/users/josiah-s-carberry/)
 * (@josiah-s-carberry)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/undefined-index-mbstring/#post-15566665)
 * debug.log sent as requested

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

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 * 4 replies
 * 2 participants
 * Last reply from: [Ambyomoron](https://wordpress.org/support/users/josiah-s-carberry/)
 * Last activity: [4 years, 1 month ago](https://wordpress.org/support/topic/undefined-index-mbstring/#post-15566665)
 * Status: resolved