FATAL ERROR

Uncaught TypeError: ESSENCE\MODELS\profileModel::generate_avatar(): Argument #1 ($avatar) must be of type string, null given, called in /home/essence/public_html/.essence/models/profileModel.php on line 126 and defined in /home/essence/public_html/.essence/models/profileModel.php:241Stack trace:#0 /home/essence/public_html/.essence/models/profileModel.php(126): ESSENCE\MODELS\profileModel::generate_avatar(NULL, NULL)#1 /home/essence/public_html/.essence/controllers/homeController.php(77): ESSENCE\MODELS\profileModel::fetch('sitemap.xml')#2 /home/essence/public_html/.essence/routing/routing.php(204): ESSENCE\CONTROLLERS\homeController::profile(Array, Array)#3 /home/essence/public_html/.essence/essence.php(403): ESSENCE\ROUTING\Routing->dispatch('get', 'sitemap.xml')#4 /home/essence/public_html/.essence/essence.php(387): ESSENCE\Essence->load_web()#5 /home/essence/public_html/.essence/essence.php(206): ESSENCE\Essence->load_http()#6 /home/essence/public_html/index.php(46): ESSENCE\Essence->run()#7 {main} thrown
in file: /home/essence/public_html/.essence/models/profileModel.php - on line: 241