OO ALV F4 help - short dump with GETWA_NOT_ASSIGNED

Hello All,

I try to use F4 help of a column in the ALV grid and got a short dump GETWA_NOT_ASSIGNED.

when fill fieldcat, reference table & field name from a table/field with f4.

We are using OO ALV display. For F4 event, a handle_F4_event method has been written, the fields have been registered for F4 display.

Any help is highly appreciated.

kv