Issue

When Discovery is run against a target system, the following error message is seen in the discovery log:

CMDB identification error: Missing required attribute:'attribute_name'

where 'attribute_name' is the field name.

Solution

In the Discovery log, look for the Source field identifier associated with the error message.
Navigate to Configuration > Identification/Reconciliation > CI Identifiers and search for the identifier, for example, Hardware Rule.
In the CI Identifier page, see which table the identifier applies to, for example, if it applies to, for example, Hardware (cmdb_ci_hardware).
Navigate to System Definition > Tables and search for the table, for example, Hardware.
In the Table columns, add the Mandatory field into the view and search for mandatory fields set to true. If the field matches the missing required attribute in step 1, then set the mandatory field to false.

You may also need to check the parent tables for the CI class (for example, mandatory fields on cmdb_ci that are not present on child tables