Magento 2.2.0 Invalid Document Element 'resource': The attribute 'title' is required but missing

1down vote

I had this same problem recently. A couple of observations and a workaround.

1) It would help immensely if instead of 'Invalid Document' it told you which document was invalid.

2) The setup:upgrade process should probably do some pre-flight checks to make sure it can do the upgrade.

Anyway, if you're stuck trying to find a missing title in the dozens of acl.xml files, but need to get a site back online quick, the quick workaround is to make the title attribute optional instead of required.

Edit vendor/magento/framework/Acl/etc/acl_merged.xsd

Find the line

<xs:attribute name="title" type="typeTitle" use="required" />

replace with

<xs:attribute name="title" type="typeTitle" use="optional" />

re-run magento setup:upgrade