Got this problem after installing new module using composer. Module has been removed already but error still is present. This error appears only after trying to log into backend. Frontend as well as backend login screen works as intended. Magento 2 system.log shows the same error, not sure how to debug this.
1 exception(s):
Exception #0 (Exception): Warning: DOMDocument::loadXML(): Empty string supplied as input in /var/www/portostock/vendor/magento/framework/Config/Dom.php on line 386
Exception #0 (Exception): Warning: DOMDocument::loadXML(): Empty string supplied as input in /var/www/portostock/vendor/magento/framework/Config/Dom.php on line 386
<pre>#1 DOMDocument->loadXML('') called at [vendor/magento/framework/Config/Dom.php:386]
#2 Magento\Framework\Config\Dom->_initDom('') called at [vendor/magento/framework/Config/Dom.php:147]
#3 Magento\Framework\Config\Dom->merge('') called at [vendor/magento/framework/Config/Reader/Filesystem.php:151]
#4 Magento\Framework\Config\Reader\Filesystem->_readFiles(&Magento\Framework\Config\FileIterator#000000003ab0cbec000000007a29194d#) called at [vendor/magento/framework/Config/Reader/Filesystem.php:130]
#5 Magento\Framework\Config\Reader\Filesystem->read('adminhtml') called at [vendor/magento/module-backend/Model/Menu/Config.php:144]
#6 Magento\Backend\Model\Menu\Config->_initMenu() called at [vendor/magento/module-backend/Model/Menu/Config.php:111]
#7 Magento\Backend\Model\Menu\Config->getMenu() called at [vendor/magento/module-backend/Model/Url.php:364]
#8 Magento\Backend\Model\Url->_getMenu() called at [vendor/magento/module-backend/Model/Url.php:324]
#9 Magento\Backend\Model\Url->getStartupPageUrl() called at [generated/code/Magento/Backend/Model/Url/Interceptor.php:102]
#10 Magento\Backend\Model\Url\Interceptor->getStartupPageUrl() called at [vendor/magento/module-backend/App/AbstractAction.php:282]
#11 Magento\Backend\App\AbstractAction->_processUrlKeys() called at [generated/code/Magento/Backend/Controller/Adminhtml/Cache/Index/Interceptor.php:50]
#12 Magento\Backend\Controller\Adminhtml\Cache\Index\Interceptor->_processUrlKeys() called at [vendor/magento/module-backend/App/AbstractAction.php:208]
#13 Magento\Backend\App\AbstractAction->dispatch(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/framework/Interception/Interceptor.php:58]
#14 Magento\Backend\Controller\Adminhtml\Cache\Index\Interceptor->___callParent('dispatch', array(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#)) called at [vendor/magento/framework/Interception/Interceptor.php:138]
#15 Magento\Backend\Controller\Adminhtml\Cache\Index\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/module-backend/App/Action/Plugin/Authentication.php:143]
#16 Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(&Magento\Backend\Controller\Adminhtml\Cache\Index\Interceptor#000000003ab0ccab000000007a29194d#, &Closure#000000003ab0ccad000000007a29194d#, &Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/framework/Interception/Interceptor.php:135]
#17 Magento\Backend\Controller\Adminhtml\Cache\Index\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/framework/Interception/Interceptor.php:153]
#18 Magento\Backend\Controller\Adminhtml\Cache\Index\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#), NULL) called at [generated/code/Magento/Backend/Controller/Adminhtml/Cache/Index/Interceptor.php:39]
#19 Magento\Backend\Controller\Adminhtml\Cache\Index\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/framework/App/FrontController.php:55]
#20 Magento\Framework\App\FrontController->dispatch(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/framework/Interception/Interceptor.php:58]
#21 Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', array(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#)) called at [vendor/magento/framework/Interception/Interceptor.php:138]
#22 Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/framework/Interception/Interceptor.php:153]
#23 Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', array(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#), array(array('default_store_se...', 'storeCookieValid...', 'install', 'configHash'))) called at [generated/code/Magento/Framework/App/FrontController/Interceptor.php:26]
#24 Magento\Framework\App\FrontController\Interceptor->dispatch(&Magento\Framework\App\Request\Http#000000003ab0cf67000000007a29194d#) called at [vendor/magento/framework/App/Http.php:136]
#25 Magento\Framework\App\Http->launch() called at [generated/code/Magento/Framework/App/Http/Interceptor.php:24]
#26 Magento\Framework\App\Http\Interceptor->launch() called at [vendor/magento/framework/App/Bootstrap.php:257]
#27 Magento\Framework\App\Bootstrap->run(&Magento\Framework\App\Http\Interceptor#000000003ab0cf16000000007a29194d#) called at [pub/index.php:37]
</pre>
Does anyone know how to solve it? Thanks in advance.