Appears after the Update from Version 2.x to 3.x.
Getting the Profile Vistitor Popup returns this error messag: Piwik encoutered an error: Class ‘Piwik\Plugin\Settings’ not found (which lead to: Class ‘Piwik\Plugin\Settings’ not found)
Stacktrace:
#0 [internal function]: Piwik\Plugins\CorePluginsAdmin\Controller->safemode(Array)
#1 /var/www/piwik/core/FrontController.php(542): call_user_func_array(Array, Array)
#2 /var/www/piwik/core/FrontController.php(137): Piwik\FrontController->doDispatch(‘CorePluginsAdmi…’, ‘safemode’, Array)
#3 /var/www/piwik/core/FrontController.php(88): Piwik\FrontController->dispatch(‘CorePluginsAdmi…’, ‘safemode’, Array)
#4 /var/www/piwik/core/FrontController.php(229): Piwik\FrontController::generateSafeModeOutputFromError(Array)
#5 [internal function]: Piwik\FrontController::triggerSafeModeWhenError()
#6 {main}