File Status 9/161 when opening a file with CALL 'EXTFH'

[Migrated content. Thread originally posted on 04 February 2011]

In order to bind ISAM data to ADO controls, we have set up a trial project in Visual Cobol R3 that uses the Microfocus File Handler (we also use this in our NetExpress 4.0 projects).
Opening a file with call 'EXTFH' returns a file status 9/161 (something wrong with the file header?).
When running the same code in NetExpress, this returns a file status zero (which is ok).
Does someone know what might be the solution to this problem?