If the routine ^%ETRSDK was located in the default % namespace, your errortrap routine was probably erased in a Caché Upgrade (only %Z routines will remain there after an upgrade)

You can use

Try {

  //your code

} catch err {

  //handle the error

}

See https://docs.intersystems.com/iris20251/csp/docbook/DocBook.UI.Page.cls?...

Friendly Regards,
Danny

Any idea how to hide these health check logs in the audit events, so only 'real' login failure attempts are shown ?

You can also use the open exchange solution from Lorenzo Scalese :
https://openexchange.intersystems.com/package/IO-Redirect