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support@neosinner After update> update error > deleted/reinstall > WP doesn’t let me as the plugin caused a fatal error and this is somehow recorded in the WP database. Did upload the plugin manually without success (Error like: The plugin triggered a fatal error before and can’t be installed) So I can’t use the plugin anymore? Help please. Thanks.
@vivobook do you please have specific error from server logs? That could help us to determine if the issue is failed migration, or conflict with some other plugin/theme
@neosinner , I don’t have, sorry. I used MP for a long time and did not install any new plugin. I found a guideline on how to install the plugin into a new folder, so that the database don’t trigger an error again. Will try that or if you have any other suggestion?
I had the same problem. Here’s the activation error I got with WordPress 6.9.4, PHP 8.2 and MailPoet 5.26.1: [18-May-2026 18:11:01 UTC] PHP Fatal error: Uncaught Error: Call to undefined function mb_strtolower() in /home/jfubz730ohsb/public_html/wp-content/plugins/mailpoet/vendor-prefixed/nesbot/carbon/src/Carbon/Traits/Date.php:2084
Problem solved by adding the mbstring PHP extension. Apparently previously-enabled extensions aren’t automatically enabled when upgrading to a newer PHP version on a GoDaddy-hosted website. Log in, manage hosting, cPanel admin-> PHP Selector and you’ll see a list of available extensions. Scroll down and check the box next to mbstring. Then go back to your plugins page and activate MailPoet.
Hi @loehoafaq , Thanks for letting us know what worked to fix this issue. We are glad you found the solution and fixed it and shared it for others who might run into this issue. We appreciate it.
@vivobook do you please have specific error from server logs? That could help us to determine if the issue is failed migration, or conflict with some other plugin/theme
@neosinner , I don’t have, sorry. I used MP for a long time and did not install any new plugin. I found a guideline on how to install the plugin into a new folder, so that the database don’t trigger an error again. Will try that or if you have any other suggestion?
I had the same problem. Here’s the activation error I got with WordPress 6.9.4, PHP 8.2 and MailPoet 5.26.1: [18-May-2026 18:11:01 UTC] PHP Fatal error: Uncaught Error: Call to undefined function mb_strtolower() in /home/jfubz730ohsb/public_html/wp-content/plugins/mailpoet/vendor-prefixed/nesbot/carbon/src/Carbon/Traits/Date.php:2084
Problem solved by adding the mbstring PHP extension. Apparently previously-enabled extensions aren’t automatically enabled when upgrading to a newer PHP version on a GoDaddy-hosted website. Log in, manage hosting, cPanel admin-> PHP Selector and you’ll see a list of available extensions. Scroll down and check the box next to mbstring. Then go back to your plugins page and activate MailPoet.
Hi @loehoafaq , Thanks for letting us know what worked to fix this issue. We are glad you found the solution and fixed it and shared it for others who might run into this issue. We appreciate it.