When we run php bin/magento setup:upgrade command through the command line, Sometimes error will throw like, Invalid Document Element ‘resource’: The attribute ‘title’ is required but missing.
This issue coming to Magento 2.2.* version when you run upgrade command.
This issue is related to acl.xml file. You missing the title attribute to <resource> tag. You must declare all the resource tag in acl.xml file with title attribute except all the resource tag which start with id=”Magento_Backend::”.
Check error code,
<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="urn:magento:framework:Acl/etc/acl.xsd">
<acl>
<resources>
<resource id="Magento_Backend::admin">
<resource id="Rbj_CustomForm::rbj">
<resource id="Rbj_CustomForm::customform" title="Customform Main" sortOrder="10">
<resource id="Rbj_CustomForm::manage_customform" title="Manage Customform" sortOrder="10" />
</resource>
</resource>
</resource>
</resources>
</acl>
</config>
<resource id=”Rbj_CustomForm::rbj”> this tag with title attribute is missing, So you must set tag with title=”title name”.
Right code,
<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="urn:magento:framework:Acl/etc/acl.xsd">
<acl>
<resources>
<resource id="Magento_Backend::admin">
<resource id="Rbj_CustomForm::rbj" title="Customform">
<resource id="Rbj_CustomForm::customform" title="Customform Slider" sortOrder="10">
<resource id="Rbj_CustomForm::manage_customform" title="Manage Customform" sortOrder="10" />
</resource>
</resource>
</resource>
</resources>
</acl>
</config>
Run Setup upgrade command and your error will be wiped out.
php magento setup:upgrade