Migrating and Upgrading to Joomla! 4.x • Update - 0 Class "JObserverMapper" not found

Hey,

I have a big problem after updating to 4.X:

0 Class "JObserverMapper" not found

Call stack
# Function Location
1 () JROOT/plugins/system/modulehistory/modulehistory.php:58
2 PlgSystemModuleHistory->onAfterInitialise() JROOT/libraries/src/Plugin/CMSPlugin.php:289
3 Joomla\CMS\Plugin\CMSPlugin->Joomla\CMS\Plugin\{closure}() JROOT/libraries/vendor/joomla/event/src/Dispatcher.php:486
4 Joomla\Event\Dispatcher->dispatch() JROOT/libraries/src/Application/EventAware.php:111
5 Joomla\CMS\Application\WebApplication->triggerEvent() JROOT/libraries/src/Application/CMSApplication.php:745
6 Joomla\CMS\Application\CMSApplication->initialiseApp() JROOT/libraries/src/Application/AdministratorApplication.php:312
7 Joomla\CMS\Application\AdministratorApplication->initialiseApp() JROOT/libraries/src/Application/AdministratorApplication.php:165
8 Joomla\CMS\Application\AdministratorApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:293
9 Joomla\CMS\Application\CMSApplication->execute() JROOT/administrator/includes/app.php:61
10 require_once() JROOT/administrator/index.php:32

Does anybody know how to solve this problem?

Many thanks and kind regards
Jan

Statistics: Posted by JanCMartin — Tue Jan 16, 2024 9:37 am

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