>"The key defined by the KeyField Property for table dbc.table is not unique". Seems like a simple message, but I don't really understand what it means.
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> Get this error when trying to delete or update from the view. The table has one key field that it's indexed on, the view is indexed on the same key field name. Have clicked on the key field on the update tab and those fields to update. Don't understand the problem.

It alerts you that key field is really not unique. Try, as a check, to make Candidate index tag on this field.