On login to Magento 2.1 admin I get following error .
1 exception(s):
Exception #0 (LogicException): Could not create an acl object: Invalid Document
Element 'admin': This element is not expected. Expected is ( resource ).
Line: 5
Exception #0 (LogicException): Could not create an acl object: Invalid Document
Element 'admin': This element is not expected. Expected is ( resource ).
Line: 5
#0 /var/www/html/Dir/var/generation/Magento/Framework/Acl/Builder/Proxy.php(95): Magento\Framework\Acl\Builder->getAcl()
#1 /var/www/html/Dir/vendor/magento/module-backend/Model/Auth/Session.php(221): Magento\Framework\Acl\Builder\Proxy->getAcl()
#2 /var/www/html/Dir/var/generation/Magento/Backend/Model/Auth/Session/Interceptor.php(102): Magento\Backend\Model\Auth\Session->processLogin()
#3 /var/www/html/Dir/vendor/magento/module-backend/Model/Auth.php(156): Magento\Backend\Model\Auth\Session\Interceptor->processLogin()
#4 /var/www/html/Dir/vendor/magento/framework/Interception/Interceptor.php(146): Magento\Backend\Model\Auth->login('*****', '*****')
#5 /var/www/html/Dir/var/generation/Magento/Backend/Model/Auth/Interceptor.php(78): Magento\Backend\Model\Auth\Interceptor->___callPlugins('login', Array, Array)
#6 /var/www/html/Dir/vendor/magento/module-backend/App/Action/Plugin/Authentication.php(205): Magento\Backend\Model\Auth\Interceptor->login('*****', '*****')
#7 /var/www/html/Dir/vendor/magento/module-backend/App/Action/Plugin/Authentication.php(157): Magento\Backend\App\Action\Plugin\Authentication->_performLogin(Object(Magento\Framework\App\Request\Http))
#8 /var/www/html/Dir/vendor/magento/module-backend/App/Action/Plugin/Authentication.php(125): Magento\Backend\App\Action\Plugin\Authentication->_processNotLoggedInUser(Object(Magento\Framework\App\Request\Http))
#9 /var/www/html/Dir/vendor/magento/framework/Interception/Chain/Chain.php(67): Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(Object(Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#10 /var/www/html/Dir/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Backend...', 'dispatch', Object(Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor), Array, 'adminMassaction...')
#11 /var/www/html/Dir/vendor/magento/module-backend/App/Action/Plugin/MassactionKey.php(33): Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#12 /var/www/html/Dir/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Backend\App\Action\Plugin\MassactionKey->aroundDispatch(Object(Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#13 /var/www/html/Dir/var/generation/Magento/Backend/Controller/Adminhtml/Index/Index/Interceptor.php(39): Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->___callPlugins('dispatch', Array, Array)
#14 /var/www/html/Dir/vendor/magento/framework/App/FrontController.php(55): Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#15 /var/www/html/Dir/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#16 /var/www/html/Dir/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#17 /var/www/html/Dir/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
#18 /var/www/html/Dir/vendor/magento/framework/Module/Plugin/DbStatusValidator.php(69): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#19 /var/www/html/Dir/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#20 /var/www/html/Dir/var/generation/Magento/Framework/App/FrontController/Interceptor.php(26): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, Array)
#21 /var/www/html/Dir/vendor/magento/framework/App/Http.php(135): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#22 /var/www/html/Dir/vendor/magento/framework/App/Bootstrap.php(258): Magento\Framework\App\Http->launch()
#23 /var/www/html/Dir/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
#24 {main}
How to debug it and find the root cause that is which acl file is creating this issue?