In one customer site my VFP 9 application causes error

Variable '_REPORTOUTPUT' is not found.

at line

DO (_reportoutput) WITH 5, olistener


I'm unable to reproduce this in my development computer. In other customer sites the error does not occur.

Any idea how to fix this ?

I have the following code in my application init code to include all required components into exe file:

SET ENGINEBEHAVIOR 90
SET REPORTBEHAVIOR 80
_REPORTBUILDER = "frxbuilder.prg"
_REPORTPREVIEW = "frxpreview.prg"
_REPORTOUTPUT = "frxoutput.prg"
EXTERNAL PROCEDURE frxbuilder.prg,frxpreview.prg,frxoutput.prg