http://localhost:8080/magento2/admin_wiyj04/admin/index/index/key/ad7a5dd1c113ab559c6aa545e7ffac7946

[BYK]

Post login into my localhost admin panel, throwing an error message like below.

1 exception(s):
Exception #0 (LogicException): Could not create an acl object: Invalid Document 
Element 'resource': The attribute 'title' is required but missing.
Line: 26


Exception #0 (LogicException): Could not create an acl object: Invalid Document 
Element 'resource': The attribute 'title' is required but missing.
Line: 26

<pre>#1 Magento\Framework\Acl\Builder\Proxy->getAcl() called at [vendor\magento\module-backend\Model\Auth\Session.php:229]
#2 Magento\Backend\Model\Auth\Session->processLogin() called at [generated\code\Magento\Backend\Model\Auth\Session\Interceptor.php:102]
#3 Magento\Backend\Model\Auth\Session\Interceptor->processLogin() called at [vendor\magento\module-backend\Model\Auth.php:165]
#4 Magento\Backend\Model\Auth->login('mmg', 'mmg@123') called at [vendor\magento\framework\Interception\Interceptor.php:58]
#5 Magento\Backend\Model\Auth\Interceptor->___callParent('login', array('mmg', 'mmg@123')) called at [vendor\magento\framework\Interception\Interceptor.php:138]
#6 Magento\Backend\Model\Auth\Interceptor->Magento\Framework\Interception\{closure}('mmg', 'mmg@123') called at [vendor\magento\framework\Interception\Interceptor.php:153]
#7 Magento\Backend\Model\Auth\Interceptor->___callPlugins('login', array('mmg', 'mmg@123'), array(array('security_admin_s...'))) called at [generated\code\Magento\Backend\Model\Auth\Interceptor.php:78]
#8 Magento\Backend\Model\Auth\Interceptor->login('mmg', 'mmg@123') called at [vendor\magento\module-backend\App\Action\Plugin\Authentication.php:205]
#9 Magento\Backend\App\Action\Plugin\Authentication->_performLogin(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\module-backend\App\Action\Plugin\Authentication.php:157]
#10 Magento\Backend\App\Action\Plugin\Authentication->_processNotLoggedInUser(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\module-backend\App\Action\Plugin\Authentication.php:125]
#11 Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(&Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor#00000000584d735d0000000031d8c6ad#, &Closure#00000000584d735c0000000031d8c6ad#, &Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\framework\Interception\Interceptor.php:135]
#12 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\framework\Interception\Interceptor.php:153]
#13 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#), NULL) called at [generated\code\Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor.php:39]
#14 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->dispatch(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\framework\App\FrontController.php:162]
#15 Magento\Framework\App\FrontController->processRequest(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#, &Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor#00000000584d735d0000000031d8c6ad#) called at [vendor\magento\framework\App\FrontController.php:98]
#16 Magento\Framework\App\FrontController->dispatch(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\framework\Interception\Interceptor.php:58]
#17 Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', array(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#)) called at [vendor\magento\framework\Interception\Interceptor.php:138]
#18 Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\framework\Interception\Interceptor.php:153]
#19 Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#), array(array('default_store_se...', 'page_cache_from_...', 'storeCookieValid...', 'install', 'configHash'))) called at [generated\code\Magento\Framework\App\FrontController\Interceptor.php:26]
#20 Magento\Framework\App\FrontController\Interceptor->dispatch(&Magento\Framework\App\Request\Http#00000000584d710d0000000031d8c6ad#) called at [vendor\magento\framework\App\Http.php:116]
#21 Magento\Framework\App\Http->launch() called at [generated\code\Magento\Framework\App\Http\Interceptor.php:24]
#22 Magento\Framework\App\Http\Interceptor->launch() called at [vendor\magento\framework\App\Bootstrap.php:261]
#23 Magento\Framework\App\Bootstrap->run(&Magento\Framework\App\Http\Interceptor#00000000584d711e0000000031d8c6ad#) called at [index.php:39]
</pre>

[Manish Mittal]

@BYK 

 the problem is one of your custom or third party module contains <resource> tag in acl.xml in etc folder file and the title attribute is missing over there, which is the cause of this exception. Therefore, I would suggest you to check acl.xml files and if title attribute is missing in any of your module then add a title to <resource> tag something like this:

File etc/acl.xml in one of your module:

<resource id="Custom_Module::config" title="Module Title" />

[BYK]

@Manish Mittal 

I have tried but no luck!

1 exception(s):
Exception #0 (LogicException): Could not create an acl object: Invalid Document 
Element 'resource': The attribute 'title' is required but missing.
Line: 26


Exception #0 (LogicException): Could not create an acl object: Invalid Document 
Element 'resource': The attribute 'title' is required but missing.
Line: 26

<pre>#1 Magento\Framework\Acl\Builder\Proxy->getAcl() called at [vendor\magento\module-backend\Model\Auth\Session.php:229]
#2 Magento\Backend\Model\Auth\Session->processLogin() called at [generated\code\Magento\Backend\Model\Auth\Session\Interceptor.php:102]
#3 Magento\Backend\Model\Auth\Session\Interceptor->processLogin() called at [vendor\magento\module-backend\Model\Auth.php:165]
#4 Magento\Backend\Model\Auth->login('mmg', 'mmg@123') called at [vendor\magento\framework\Interception\Interceptor.php:58]
#5 Magento\Backend\Model\Auth\Interceptor->___callParent('login', array('mmg', 'mmg@123')) called at [vendor\magento\framework\Interception\Interceptor.php:138]
#6 Magento\Backend\Model\Auth\Interceptor->Magento\Framework\Interception\{closure}('mmg', 'mmg@123') called at [vendor\magento\framework\Interception\Interceptor.php:153]
#7 Magento\Backend\Model\Auth\Interceptor->___callPlugins('login', array('mmg', 'mmg@123'), array(array('security_admin_s...'))) called at [generated\code\Magento\Backend\Model\Auth\Interceptor.php:78]
#8 Magento\Backend\Model\Auth\Interceptor->login('mmg', 'mmg@123') called at [vendor\magento\module-backend\App\Action\Plugin\Authentication.php:205]
#9 Magento\Backend\App\Action\Plugin\Authentication->_performLogin(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\module-backend\App\Action\Plugin\Authentication.php:157]
#10 Magento\Backend\App\Action\Plugin\Authentication->_processNotLoggedInUser(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\module-backend\App\Action\Plugin\Authentication.php:125]
#11 Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(&Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor#000000004e9f6fc50000000048740e68#, &Closure#000000004e9f6fc40000000048740e68#, &Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\framework\Interception\Interceptor.php:135]
#12 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\framework\Interception\Interceptor.php:153]
#13 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#), NULL) called at [generated\code\Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor.php:39]
#14 Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\framework\App\FrontController.php:162]
#15 Magento\Framework\App\FrontController->processRequest(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#, &Magento\Backend\Controller\Adminhtml\Index\Index\Interceptor#000000004e9f6fc50000000048740e68#) called at [vendor\magento\framework\App\FrontController.php:98]
#16 Magento\Framework\App\FrontController->dispatch(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\framework\Interception\Interceptor.php:58]
#17 Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', array(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#)) called at [vendor\magento\framework\Interception\Interceptor.php:138]
#18 Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\framework\Interception\Interceptor.php:153]
#19 Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#), array(array('default_store_se...', 'page_cache_from_...', 'storeCookieValid...', 'install', 'configHash'))) called at [generated\code\Magento\Framework\App\FrontController\Interceptor.php:26]
#20 Magento\Framework\App\FrontController\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000004e9f6d950000000048740e68#) called at [vendor\magento\framework\App\Http.php:116]
#21 Magento\Framework\App\Http->launch() called at [generated\code\Magento\Framework\App\Http\Interceptor.php:24]
#22 Magento\Framework\App\Http\Interceptor->launch() called at [vendor\magento\framework\App\Bootstrap.php:261]
#23 Magento\Framework\App\Bootstrap->run(&Magento\Framework\App\Http\Interceptor#000000004e9f6d860000000048740e68#) called at [index.php:39]
</pre>

[Manish Mittal]

@BYK 

Did you findout that module, in which that title is missing? if yes and you made already correction just do flush cache. It will work. 

[Sunil Patel]

Hello @BYK 

go to your env.php and disable one by one module that is third party module and check it

[Manish Mittal]

@BYK 

It should be in config.php file not in env.php. Modules defined in config.php where you can disable to check. 

cc: @Sunil Patel 

[Manish Mittal]

[BYK]

@Manish Mittal 

CC: @Sunil Patel 

I have tried with this and finally solved it.

I have installed "Core module" which can be found here https://github.com/mageplaza/module-core

Install

composer require mageplaza/module-core
php bin/magento setup:upgrade
php bin/magento setup:static-content:deploy

Upgrade

composer update mageplaza/module-core
php bin/magento setup:upgrade
php bin/magento setup:static-content:deploy

[Manish Mittal]

@BYK 

Great! pleasure to help you.