Setup upgrade Error, Invalid Document Element ‘resource’: The attribute ‘title’ is required but missing Magento 2

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