Yii2 --- PHP Notice 'yii\base\ErrorException' with message 'unserialize(): Error at offset 8189 of 8192 bytes' -

php notice 'yii\base\errorexception' message 'unserialize(): error @ offset 8189 of 8192 bytes'   in c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2-debug\controllers\defaultcontroller.php:132  stack trace: #0 [internal function]: yii\base\errorhandler->handleerror(8, 'unserialize(): ...', 'c:\\xampp\\htdocs...', 132, array) #1 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2-debug\controllers\defaultcontroller.php(132): unserialize('a:58:{s:13:"55a...') #2 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2-debug\controllers\defaultcontroller.php(147): yii\debug\controllers\defaultcontroller->getmanifest(false) #3 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2-debug\controllers\defaultcontroller.php(92): yii\debug\controllers\defaultcontroller->loaddata('55a8abf042085', 5) #4 [internal function]: yii\debug\controllers\defaultcontroller->actiontoolbar('55a8abf042085') #5 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2\base\inlineaction.php(55): call_user_func_array(array, array) #6 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2\base\controller.php(151): yii\base\inlineaction->runwithparams(array) #7 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2\base\module.php(455): yii\base\controller->runaction('toolbar', array) #8 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2\web\application.php(84): yii\base\module->runaction('debug/default/t...', array) #9 c:\xampp\htdocs\final\advanced\vendor\yiisoft\yii2\base\application.php(375): yii\web\application->handlerequest(object(yii\web\request)) #10 c:\xampp\htdocs\final\advanced\backend\web\index.php(18): yii\base\application->run() #11 {main} 

getting error while running yii2 application whats wrong ?

looks problem in cached version of request data. try clearing folder under @runtime/debug.