Preference table/database flawed in prod, how to repair?

Document ID : KB000107937
Last Modified Date : 27/07/2018
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encountered in case 0114XXXX. Preference table could not be updated/modified. In test/QA, was able to recover by removing the DB, creating a new DB from the SQL DDL and it worked. But how do they recover without disruption or loss in Prod?
move the necessary changes into 12.1 Web Viewer on production. After creating a new DB (RWE permissions needed) from the supplied DDL, change to point to the new DB - JDBC URL - either manually, or using the ConfigTool. Make sure the first person to log into Web Viewer after such changes, is the one referenced in Finally, import the tables from Web Viewer (how to export, then import).