Title: Error with version 5.21.0 Last modified: December 17, 2025 --- # Error with version 5.21.0 * Resolved [Dzynit](https://wordpress.org/support/users/dzynit/) * (@dzynit) * [4 months, 3 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/) * I’m getting this error on multiple sites when upgrading through managewp: Class‘ Simple_History\Channels\Channels\File_Channel’ not found occurred in wp-content/ plugins/simple-history/inc/channels/class-channels-manager.php on line 50 * Sites are still online when checked, seem to have finished upgrades – but it’s concerning to deal with when you work with many sites. * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ferror-with-version-5-21-0%2F%3Foutput_format%3Dmd&locale=en_US) to see the link]_ Viewing 13 replies - 1 through 13 (of 13 total) * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [4 months, 3 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18758959) * Thanks for the report. Not sure what this could be. I can not reproduce it and I get no errors on any of the sites that I have updated on and all my tests including [phpstan](https://phpstan.org/) passes. * Could you share some info about your hosting, like what web server, php version, and so on? * Thread Starter [Dzynit](https://wordpress.org/support/users/dzynit/) * (@dzynit) * [4 months, 3 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18759596) * The sites it’s happened on are all on WPEngine and running php 8.2. * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [4 months, 3 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18759600) * Thanks. Does the message only appear once (during update?) and then the plugin is updated and the websites seem to work fine? * Thread Starter [Dzynit](https://wordpress.org/support/users/dzynit/) * (@dzynit) * [4 months, 3 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18759605) * Yes, just the once and I’ve checked the sites and the plugin seems fine afterwards. * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [4 months, 3 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18762267) * Version 5.22.0 of the plugin is out now with perhaps/hopefully a fix for this. * Thread Starter [Dzynit](https://wordpress.org/support/users/dzynit/) * (@dzynit) * [4 months, 2 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18766153) * The new update has the same error, but it triggers a database update and stops the rest of the updates for other plugins. * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [4 months, 1 week ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18770893) * I still have not got this error on any of my test sites or production sites. I wonder if it somehow could be an incompatibility with another plugin. Any chance you could let me know what plugins you have activated and also what theme that is active? * Thread Starter [Dzynit](https://wordpress.org/support/users/dzynit/) * (@dzynit) * [4 months, 1 week ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18770912) * The plugins and themes vary from site to site, so the only specifically in common on all is that the hosting is wpengine and they all have the managewp plugin so they can be updated using managewp. * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [4 months ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18776688) * Thanks for the follow up. This sure seems like an issue on wpengine. I’m investigating but don’t have an account there so can’t really test anything for real… * Thread Starter [Dzynit](https://wordpress.org/support/users/dzynit/) * (@dzynit) * [4 months ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18777047) * Thank you so very much for continuing to follow up! I know it’s tough when it’s narrowed to a certain environment you don’t have. * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [3 months ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18813551) * Hey, an update regarding this: * I have really tried to identify what could cause this, but without success. * I have tried to debug with all kinds of tools, and I have confired docker images with case sensitive file system, if that could be the case? I have also tried it on many different WordPress versions, still working. And on many live real hosts too. It works everywhere for me so it’s quite frustrating. There is something going on with…wpengine? managewp? Or perhaps another plugin or host setup combination… * I have waited a while now to see if more users have this problem, but no support emails and no more support threads the last month now. So right now I can just wait and see if it happens again in the next version – and if it does I would be greateful if you could send as much debug info (wp version, php version, host setup, active plugin, active theme…) as possible here or to the email at [https://simple-history.com/contact](https://simple-history.com/contact) if it contains any sensitive info. * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [2 months, 2 weeks ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18832012) * Please try updating again and let med know if the latest version solves this. * Plugin Author [Pär Thernström](https://wordpress.org/support/users/eskapism/) * (@eskapism) * [2 months, 1 week ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18837913) * I have not got any new reports since the last version update, so I’m guessing/ hoping this is fixed now. If you still have this issue please start a new support thread. Viewing 13 replies - 1 through 13 (of 13 total) You must be [logged in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ferror-with-version-5-21-0%2F%3Foutput_format%3Dmd&locale=en_US) to reply to this topic. * ![](https://ps.w.org/simple-history/assets/icon.svg?rev=3225008) * [Simple History – Track, Log, and Audit WordPress Changes](https://wordpress.org/plugins/simple-history/) * [Frequently Asked Questions](https://wordpress.org/plugins/simple-history/#faq) * [Support Threads](https://wordpress.org/support/plugin/simple-history/) * [Active Topics](https://wordpress.org/support/plugin/simple-history/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/simple-history/unresolved/) * [Reviews](https://wordpress.org/support/plugin/simple-history/reviews/) * 13 replies * 2 participants * Last reply from: [Pär Thernström](https://wordpress.org/support/users/eskapism/) * Last activity: [2 months, 1 week ago](https://wordpress.org/support/topic/error-with-version-5-21-0/#post-18837913) * Status: resolved