Title: Fatal error: Uncaught Error: Class ‘WP_Theme_JSON_Resolver’ not found Last modified: July 29, 2021 --- # Fatal error: Uncaught Error: Class ‘WP_Theme_JSON_Resolver’ not found * [Dee](https://wordpress.org/support/users/aloftaloft/) * (@aloftaloft) * [4 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/) * I can not access my dashboard or website. Below is the warning and fatal error message I am receiving. I have tried to several troubleshooting options including deactivating the plugins, deleting files and reinstalling the download, but nothing is working so far. Any help is appreciated. * **Warning:** call_user_func_array() expects parameter 1 to be a valid callback, function ‘wp_enable_block_templates’ not found or invalid function name in aloftaloft. com\wp-includes\class-wp-hook.php on line 303 * **Fatal error:** Uncaught Error: Class ‘WP_Theme_JSON_Resolver’ not found in aloftaloft.com\wp-includes\script-loader.php:1530 Stack trace: #0 aloftaloft. com\wp-includes\class-wp-hook.php(303): wp_default_styles(Object(WP_Styles)) # 1 aloftaloft.com\wp-includes\class-wp-hook.php(327): WP_Hook->apply_filters(”, Array) #2 aloftaloft.com\wp-includes\plugin.php(518): WP_Hook->do_action(Array)# 3 aloftaloft.com\wp-includes\class.wp-styles.php(135): do_action_ref_array(‘wp_default_styl…’, Array) #4 aloftaloft.com\wp-includes\functions.wp-styles.php(24): WP_Styles-> __construct() #5 aloftaloft.com\wp-includes\functions.wp-styles.php(176): wp_styles()# 6 aloftaloft.com\wp-login.php(96): wp_enqueue_style(‘login’) #7 aloftaloft.com\ wp-login.php(1285): login_header(‘Log In’, ”, Object(WP_Error)) #8 {main} thrown in aloftaloft.com\wp-includes\script-loader.php on line 1530` * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ffatal-error-uncaught-error-class-wp_theme_json_resolver-not-found%2F%3Foutput_format%3Dmd&locale=en_US) to see the link]_ Viewing 7 replies - 1 through 7 (of 7 total) * [a2hostingrj](https://wordpress.org/support/users/a2hostingrj/) * (@a2hostingrj) * [4 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14715407) * Did you upgrade the site? * Did you try disabling all plugins? * > [https://www.a2hosting.com/kb/installable-applications/optimization-and-configuration/wordpress2/wordpress-plugins/disabling-plugins-in-wordpress](https://www.a2hosting.com/kb/installable-applications/optimization-and-configuration/wordpress2/wordpress-plugins/disabling-plugins-in-wordpress) * Thread Starter [Dee](https://wordpress.org/support/users/aloftaloft/) * (@aloftaloft) * [4 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14715831) * Yes, a day prior to posting the error, I upgraded the site and also disabled all plugins. [@a2hostingrj](https://wordpress.org/support/users/a2hostingrj/) * [a2hostingrj](https://wordpress.org/support/users/a2hostingrj/) * (@a2hostingrj) * [4 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14717407) * > a day prior to posting the error, I upgraded * Did you perform a full backup before upgrading the site? * It might be an outdated plugin or some code modification not compatible with the new version * Thread Starter [Dee](https://wordpress.org/support/users/aloftaloft/) * (@aloftaloft) * [4 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14721146) * [@a2hostingrj](https://wordpress.org/support/users/a2hostingrj/) unfortunately I did not do a backup. Plus, the site automatically updated before I reinstalled it, so I know there is something in the update that is causing the problem. I am learning the hard way how important a backup really is. * Thread Starter [Dee](https://wordpress.org/support/users/aloftaloft/) * (@aloftaloft) * [4 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14722687) * It’s definitely something in the newest updated. So I reinstalled the 5.7.2 version and everything is working fine. * [a2hostingrj](https://wordpress.org/support/users/a2hostingrj/) * (@a2hostingrj) * [4 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14727149) * Well, I’m glad. Just make sure to change the update settings. * [cfullsteam](https://wordpress.org/support/users/cfullsteam/) * (@cfullsteam) * [4 years, 9 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14856160) * It seems this is now more important to resolve since 5.8.1 is a security patch and still causes this issue. I’ve commented on [https://wordpress.org/support/topic/fatal-error-wp_theme_json_resolver-not-found-in-manual-upgrade-to-5-8/#post-14856146](https://wordpress.org/support/topic/fatal-error-wp_theme_json_resolver-not-found-in-manual-upgrade-to-5-8/#post-14856146) with our details. Viewing 7 replies - 1 through 7 (of 7 total) The topic ‘Fatal error: Uncaught Error: Class ‘WP_Theme_JSON_Resolver’ not found’ is closed to new replies. ## Tags * [call_user_func_array](https://wordpress.org/support/topic-tag/call_user_func_array/) * [fatal error](https://wordpress.org/support/topic-tag/fatal-error/) * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/) * 7 replies * 3 participants * Last reply from: [cfullsteam](https://wordpress.org/support/users/cfullsteam/) * Last activity: [4 years, 9 months ago](https://wordpress.org/support/topic/fatal-error-uncaught-error-class-wp_theme_json_resolver-not-found/#post-14856160) * Status: not resolved ## Topics ### Topics with no replies ### Non-support topics ### Resolved topics ### Unresolved topics ### All topics