In ServiceNow, specific fields can be set as read only by default. This is defined at the sys_dictionary level.
Recover can't restore data to read only fields. To restore data to a read only field remove the read only setting.
- Set the read only field to false in ServiceNow.
- Run a full backup to identify the attribute change from "read only = true" to "read only = false".
- Rerun the restore job.