Title: JSON error
Last modified: April 13, 2022

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# JSON error

 *  Resolved [win2158](https://wordpress.org/support/users/win2158/)
 * (@win2158)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/json-error-43/)
 * When trying to save a lesson I get an error: “Updaten mislukt. De reactie is 
   geen geldige JSON-reactie.” (means something as: Update failed. The reaction 
   is not a valid JSON reaction.
 * I don’t have any idea whats causing this.
    Can you help me with this.
 * Thank

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Plugin Support [Alba](https://wordpress.org/support/users/ctdealba/)
 * (@ctdealba)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/json-error-43/#post-15562042)
 * Hi [@win2158](https://wordpress.org/support/users/win2158/)
 * Have you done any initial troubleshooting yet?
 * If not, please rule out a theme issue or a plugin conflict. I recommend testing
   things on a staging site rather than on your production (live) site. Many hosts
   provide a staging service, where you can do testing without affecting the live
   site. You can ask your host about this. If they don’t give you a staging site,
   you could try WP Staging or Duplicator:
 * [https://wordpress.org/plugins/wp-staging/](https://wordpress.org/plugins/wp-staging/)
   
   [https://wordpress.org/plugins/duplicator/](https://wordpress.org/plugins/duplicator/)
 * If you decide not to create a staging site, make sure to make a full backup of
   your site. Once done that, please do the following:
 * 1. Verify that all plugins are fully updated to the latest versions.
    2. Temporarily
   disable all plugins but Sensei (and related plugins), and see if the issue resolves.
   If it does, try activating your plugins one-by-one and try to reproduce the problem.
   If it comes back when you activate a particular plugin, you’ve found the culprit.
 * If things still don’t work properly, please try checking for a theme conflict.
 * 3. Temporarily switch to Twenty Seventeen, which is one of the default WordPress
   themes. You can do this by installing a plugin that only switches the theme for
   the current user, linked below:
 * [https://wordpress.org/plugins/theme-switcha/](https://wordpress.org/plugins/theme-switcha/)
 * If the issue resolves, you’ll need to contact your theme’s developer to see if
   they can help you troubleshoot.
 *  Plugin Support [Jay](https://wordpress.org/support/users/bluejay77/)
 * (@bluejay77)
 * [4 years, 1 month ago](https://wordpress.org/support/topic/json-error-43/#post-15586127)
 * Hi there,
 * It has been more than one week since we have heard from you, so I’m marking this
   topic as resolved.
 * But if you have any further questions or need some more help, you’re welcome 
   to reply here or open another thread.
 *  [Scott](https://wordpress.org/support/users/midipedalboards/)
 * (@midipedalboards)
 * [4 years ago](https://wordpress.org/support/topic/json-error-43/#post-15718226)
 * I had this issue and it turned out I had a mid configuration with a CDN I setup
   with Cloudfront.

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘JSON error’ is closed to new replies.

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 * Last activity: [4 years ago](https://wordpress.org/support/topic/json-error-43/#post-15718226)
 * Status: resolved