I spend some time to find out why my pdf file never should have been created even when I could see the file open by Acrobat Reader.
I found out that in source\classes\rpreview.prg, line 1789
return ::oDevice:GenHaruPdf( cFile )
this return value is a logical value.
Whereas in line 1883
if ! File( cFile ))
cFile is supposed to be a string value.
The file '.t.' will never be found