No. They run my exe file created by VFP 9.
I have got this error sometimes when runnig my app in development mode from vfp 9 but I havent exact repro.
I have both vfp 7 & 9 installed in my development computer.

>Could it be possible that they are trying to run your application under VFP8?
>
>>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