Matomo encountered an error: Uncaught Exception: Piwik and/or some plugins have been upgraded to a new version.
--> Please run the update process first. See documentation: https://matomo.org/docs/update/
in /var/www/piwik/plugins/CoreUpdater/CoreUpdater.php:67
Stack trace:
#0 [internal function]: Piwik\Plugins\CoreUpdater\CoreUpdater->dispatch()
#1 /var/www/piwik/core/EventDispatcher.php(141): call_user_func_array(Array, Array)
#2 /var/www/piwik/core/Piwik.php(809): Piwik\EventDispatcher->postEvent('Request.dispatc...', Array, false, Array)
#3 /var/www/piwik/core/FrontController.php(374): Piwik\Piwik::postEvent('Request.dispatc...')
#4 /var/www/wordpress/wp-content/plugins/wp-piwik/classes/WP_Piwik/Request/Php.php(40): Piwik\FrontController->init()
#5 /var/www/wordpress/wp-content/plugins/wp-piwik/classes/WP_Piwik/Request/Php.php(18): WP_Piwik\Request\Php->call('method=SitesMan...', 'https://piwik.k...', 'module=API&form...')
#6 /var/www/wordpress/wp-content/plugins/wp-piwik/classes/WP_Piwik/Request.php(63): WP_Piwik\Request\Php->requ (which lead to: Session must be started before any output has been sent to the browser; output started in /var/www/wordpress/wp-includes/class.wp-styles.php/290)