Converting PDF to PNG/JPG

Hello,

I own a Synology NAS (209+). Part of this NAS is a webserver.
Imagemagick and ghostscript are installed.

When I try to convert from e.g. png to jpg (see commandline below).......no
problems.

/usr/syno/bin/convert /volume1/TEMP/test.png /volume1/TEMP/test.jpg

But when I try to do the same with pdf to png (see commandline
below).......I get errors.

 /usr/syno/bin/convert /volume1/TEMP/test.pdf /volume1/TEMP/test.png

The errors:

 Warning: GenericResourceDir doesn't point to a valid resource directory.
               the -sGenericResourceDir=... option can be used to set this.
              convert: UnableToOpenConfigureFile `delegates.xml'.

Where should I set this "GenericResourceDir" and what about the
"delegates.xml"



Regards,
John