Hi Gary, thanks for your response.

>I would say that the "native" data-driven framework behaviour is preferable

Are you saying that if ProcFile.prg is in the LocalRegistry.Procedure Library List that I do not have to include it in the "set procedure to " statement? I assumed that listing it in AppMain was required because Dave had included his Codemine.prg procedure file there.

>What happens if you delete any FXP's?

I tried that - no joy.

What really puzzles me is the fact that the exact same ProcFile.fxp is perfectly usable when set from the command window, but triggers the error when set from AppMain.

Any other ideas ?

Dick