Warning: fopen(/var/www/files/usageStats/usageEventLogs/usage_events_20260725.log): Failed to open stream: Permission denied in /var/www/html/lib/pkp/classes/observers/listeners/LogUsageEvent.php on line 104

Fatal error: Uncaught TypeError: flock(): Argument #1 ($stream) must be of type resource, bool given in /var/www/html/lib/pkp/classes/observers/listeners/LogUsageEvent.php:105 Stack trace: #0 /var/www/html/lib/pkp/classes/observers/listeners/LogUsageEvent.php(105): flock() #1 /var/www/html/lib/pkp/classes/observers/listeners/LogUsageEvent.php(53): PKP\observers\listeners\LogUsageEvent->logUsageEvent() #2 /var/www/html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Events/Dispatcher.php(512): PKP\observers\listeners\LogUsageEvent->handle() #3 /var/www/html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Events/Dispatcher.php(319): Illuminate\Events\Dispatcher->Illuminate\Events\{closure}() #4 /var/www/html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Events/Dispatcher.php(299): Illuminate\Events\Dispatcher->invokeListeners() #5 /var/www/html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Foundation/helpers.php(505): Illuminate\Events\Dispatcher->dispatch() #6 /var/www/html/pages/article/ArticleHandler.php(513): event() #7 [internal function]: APP\pages\article\ArticleHandler->download() #8 /var/www/html/lib/pkp/classes/core/PKPRouter.php(327): call_user_func() #9 /var/www/html/lib/pkp/classes/core/PKPPageRouter.php(249): PKP\core\PKPRouter->_authorizeInitializeAndCallRequest() #10 /var/www/html/lib/pkp/classes/core/Dispatcher.php(157): PKP\core\PKPPageRouter->route() #11 /var/www/html/lib/pkp/classes/core/PKPApplication.php(429): PKP\core\Dispatcher->dispatch() #12 /var/www/html/index.php(21): PKP\core\PKPApplication->execute() #13 {main} thrown in /var/www/html/lib/pkp/classes/observers/listeners/LogUsageEvent.php on line 105