You need to map from a MetaStore field into CM. As AU_DOCUMENT_KEYWORDS_STRING is an IDOL field it will not work. There is a process to add additional MetaStore fields (during ingestion) by mapping from IDOL fields. Please see the steps in the following Knowledge Doc
As an example, for the AU_DOCUMENT_KEYWORDS_STRING field, you would need to perform the following:
1 - Add a new column to the ControlPointMetadata.Additional table to support the capture of the AU_DOCUMENT_KEYWORDS_STRING string value by running the following SQL:
ALTER TABLE ControlPointMetadata.Additional
ADD DocumentKeywords NVARCHAR(255) NULL ---you can call the MetaStore field whatever you like. Can match the source IDOL field if it suits
2. Configure AU_DOCUMENT_KEYWORDS_STRING data mapping using the MetaStore.MapField stored procedure by running the following SQL:
@SourceName = 'AU_DOCUMENT_KEYWORDS_STRING',
@TargetTable = 'ControlPointMetadata.Additional',
@TargetColumn = 'DocumentKeywords ',
@TargetTransform = 'ToString'
3. Refresh document ingest, import and update sequences to support the newly captured AU_DOCUMENT_EDITOR_STRING field in MetaStore by running the following SQL:
4. Restart the "ControlPoint Metastore" service to utilize the refreshed sequences.
Note: The steps above will ensure that the new MetaStore field will be captured for new document files being ingested. Existing data however will need to be re-ingested in order to capture values for this field.
I have found that an IIS restart is required before I can see the new field in the Advanced Properties list. Once you are happy the MetaStore field has been created successfully and the values are mapped over to it, then use this MetaStore field to Map to CM.