Title: Critical Error – help explain debugging log?
Last modified: December 4, 2023

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# Critical Error – help explain debugging log?

 *  Resolved [daitya](https://wordpress.org/support/users/daitya/)
 * (@daitya)
 * [2 years, 6 months ago](https://wordpress.org/support/topic/critical-error-help-explain-debugging-log/)
 * Today suddenly encountered the ‘Critical Error’ notice on two of my websites –
   both are running on the same server, and both are running outdated WP installations(
   v 5.5.13). No recent changes to the websites. 
   What I’ve done so far: Deactivated
   plugins. Opened wp-config and enabled debugging. I cannot make sense of the debugging
   log. Can anyone here explain it to me?I actually suspect that there might have
   been a recent PHP upgrade on the server (it’s shared hosting), and possibly this
   could have affected it?
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fcritical-error-help-explain-debugging-log%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

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

 *  [2h1n846](https://wordpress.org/support/users/2h1n846/)
 * (@2h1n846)
 * [2 years, 6 months ago](https://wordpress.org/support/topic/critical-error-help-explain-debugging-log/#post-17249946)
 * Hi Daitya
   Your hosting server appears to be missing the `php-json` module, which
   is crucial for web application functionalities. Please get in touch with your
   hosting provider’s support team to install the missing module.
 *  Thread Starter [daitya](https://wordpress.org/support/users/daitya/)
 * (@daitya)
 * [2 years, 6 months ago](https://wordpress.org/support/topic/critical-error-help-explain-debugging-log/#post-17250088)
 * Thank you, very helpful.
 *  Thread Starter [daitya](https://wordpress.org/support/users/daitya/)
 * (@daitya)
 * [2 years, 6 months ago](https://wordpress.org/support/topic/critical-error-help-explain-debugging-log/#post-17250793)
 * Thanks to Tuhin Ahmed (@2h1n846) the problem has been resolved. Contacted host
   support, and they discovered that a PHP upgrade on the shared server had impacted
   the WordPress installation. Have successfully upgraded WordPress, and hosting
   support reverted PHP to v7.4.
    -  This reply was modified 2 years, 6 months ago by [daitya](https://wordpress.org/support/users/daitya/).
 *  [2h1n846](https://wordpress.org/support/users/2h1n846/)
 * (@2h1n846)
 * [2 years, 6 months ago](https://wordpress.org/support/topic/critical-error-help-explain-debugging-log/#post-17250896)
 * I am glad your website is back up and running again.
   Enjoy your WordPress journey!

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

The topic ‘Critical Error – help explain debugging log?’ is closed to new replies.

## Tags

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

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 6 replies
 * 2 participants
 * Last reply from: [2h1n846](https://wordpress.org/support/users/2h1n846/)
 * Last activity: [2 years, 6 months ago](https://wordpress.org/support/topic/critical-error-help-explain-debugging-log/#post-17250896)
 * Status: resolved

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