Try calling CreateEffect with NIL DIEFFECT:
Pascal Code:
Result := g_pJoystick.CreateEffect(GUID_ConstantForce, nil, g_pEffect, nil);
if FAILED(Result) then Exit;

If this succeeded then error is in customizing your DIEFFECT record.
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How I create DIEFFECT record ?
I will try alot of any way to solve this problem but it not work.