FacebookApiException: Unsupported get request

This error shows randomly in the admin panel only, although the plugin works fine.

( ! ) FacebookApiException: Unsupported get request. in /home/grandjud/domains/grandjudo.pl/public_html/wp-content/plugins/wpmu-dev-facebook/lib/external/base_facebook.php on line 1039 Call Stack #TimeMemoryFunctionLocation 10.0004685384{main}( )../index.php:0 20.0010803160require_once( '/home/grandjud/domains/grandjudo.pl/public_html/wp-admin/admin.php' )../index.php:10 30.547568437552do_action( $tag = 'admin_init', $arg = ??? )../admin.php:111 40.559868617080call_user_func_array ( array (0 => class Wdfb_AdminPages { public $data = class Wdfb_OptionsRegistry { ... }; public $model = class Wdfb_Model { ... } }, 1 => 'handle_fb_auth_tokens', array (0 => '' )../plugin.php:405 50.559868617112Wdfb_AdminPages->handle_fb_auth_tokens( '' )../plugin.php:405 61.254768632064Wdfb_Model->get_pages_tokens( )../class_wdfb_admin_pages.php:461 71.254868632224BaseFacebook->api( '//accounts/' )../class_wdfb_model.php:300 81.254968633128call_user_func_array ( array (0 => class Facebook { protected $appId = '170140023033054'; protected $apiSecret = 'ac09a953180e9323cbe0a43edbc82299'; protected $user = 0; protected $signedRequest = NULL; protected $state = '0a4a9a2ddb181297dfa431b996b5c00f'; protected $accessToken = '170140023033054|ac09a953180e9323cbe0a43edbc82299'; protected $fileUploadSupport = FALSE }, 1 => '_graph', array (0 => '//accounts/' )../base_facebook.php:553 91.254968633464BaseFacebook->_graph( $path = '//accounts/', $method = ???, $params = ??? )../base_facebook.php:553 101.925968634760BaseFacebook->throwAPIException( $result = array ('error' => array ('message' => 'Unsupported get request.', 'type' => 'GraphMethodException') )../base_facebook.php:744