Thomas,
I've changed my rpg like

lvtemp='C:\Programme\Microsoft\VFP9.1\'
*lvtemp=ADDBS(THIS.hcStartPath)
   _REPORTOUTPUT  = lvTemp+'ReportOutput.app'
   _REPORTPREVIEW = lvTemp+'ReportPreview.app'
   _REPORTBUILDER = lvTemp+'ReportBuilder.app'

?FILE(_REPORTOUTPUT) and FILE(_REPORTPREVIEW ) and FILE(_REPORTBUILDER)

SET PATH TO C:\Programme\Microsoft\VFP9.1
SET REPORTBEHAVIOR 90
CREATE CURSOR cur1 (c1 c(10))
INSERT INTO cur1 VALUES ('1') 
INSERT INTO cur1 VALUES ('2') 
INSERT INTO cur1 VALUES ('3') 

MODIFY REPORT e:\se\temp\modrep.frx

but I get no preview. The print statement returns .t.

Agnes
>Hi Agnes,
>
>I can reproduce your problem, if there is no reportpreview.app within my PATH declaration.
>Where is your reportpreview.app located? Only in C:\Programme\Microsoft Visual FoxPro 9 ?
>I got mine within a subdirectory calles _apps and my path show to this directory. I removed the app and voilà, same error as yours.