Title: Class ” ” not found error
Last modified: June 22, 2026

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# Class ” ” not found error

 *  Resolved [dholtzman](https://wordpress.org/support/users/dholtzman/)
 * (@dholtzman)
 * [1 week, 5 days ago](https://wordpress.org/support/topic/class-not-found-error-4/)
 * Last week, some time after updating to UM 2.12.0, we had over 400 instances of
   the error pasted below in our log. The fatal error alert email identified at 
   least one page where the error was caught. By the time we checked the site, everything
   was working normally, and there does not seem to be anything unusual on the identified
   page.
 * The error has not recurred, but some time the following day, another plugin (
   ACF) apparently deactivated itself, with nothing in the log to indicate why it
   did so. We do not know whether or not this was connected to the UM issue.
 * We’d like to know why this happened and what, if anything, we need to do to prevent
   a recurrence. Thanks in advance.
 *     ```wp-block-code
       [18-Jun-2026 02:32:07 UTC] PHP Fatal error:  Uncaught Error: Class "" not found in /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/core/class-files.php:16Stack trace:#0 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/class-init.php(356): include_once()#1 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/class-init.php(1182): UM->um__autoloader('um\\core\\class-f...')#2 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/class-init.php(509): UM->files()#3 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/class-init.php(198): UM->includes()#4 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/class-init.php(96): UM->_um_construct()#5 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/class-init.php(1441): UM::instance()#6 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/class-init.php(1446): UM()#7 /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/ultimate-member.php(43): require_once('/home/concerti/...')#8 /home/concerti/public_html/wordpress/wp-settings.php(589): include_once('/home/concerti/...')#9 /home/concerti/public_html/wordpress/wp-config.php(94): require_once('/home/concerti/...')#10 /home/concerti/public_html/wordpress/wp-load.php(50): require_once('/home/concerti/...')#11 /home/concerti/public_html/wordpress/wp-blog-header.php(13): require_once('/home/concerti/...')#12 /home/concerti/public_html/index.php(17): require('/home/concerti/...')#13 {main}  thrown in /home/concerti/public_html/wordpress/wp-content/plugins/ultimate-member/includes/core/class-files.php on line 16
       ```
   

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

 *  Plugin Support [Yurii](https://wordpress.org/support/users/yuriinalivaiko/)
 * (@yuriinalivaiko)
 * [1 week, 5 days ago](https://wordpress.org/support/topic/class-not-found-error-4/#post-18945761)
 * Hello [@dholtzman](https://wordpress.org/support/users/dholtzman/)
 * This error may occur if one of the plugin files is missing or if the [Autoloading Classes](https://www.php.net/manual/en/language.oop5.autoload.php)
   work wrong.
 * Please re-install the plugin to restore files that may be lost. Make sure autoloading
   in PHP is working correctly.
 * Regards
 *  Plugin Support [andrewshu](https://wordpress.org/support/users/andrewshu/)
 * (@andrewshu)
 * [6 days, 6 hours ago](https://wordpress.org/support/topic/class-not-found-error-4/#post-18950645)
 * Hi [@dholtzman](https://wordpress.org/support/users/dholtzman/)
 * This thread has been inactive for a while so we’re going to go ahead and mark
   it Resolved.
 * Please feel free to re-open this thread if any other questions come up and we’d
   be happy to help. 🙂
 * Regards

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

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 * 2 replies
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 * Last reply from: [andrewshu](https://wordpress.org/support/users/andrewshu/)
 * Last activity: [6 days, 6 hours ago](https://wordpress.org/support/topic/class-not-found-error-4/#post-18950645)
 * Status: resolved