Jasper viewer: save as excel doesn't work

Hi

When I would like to save a report in the Jasper Viewer (push the save
button) I have the possibility to save as “Single sheet XLS (.xls)"
or "Multiple sheet XLS (
.xls)”. In my case, none of them is working.
I think there are some libraries missing? Does anybody know which
libraries are missing here?

In the install.txt of the Jasper plugin I found the following hint:
“EXCEL AND CHART SUPPORT
Additionally, when requiring Chart and Excel support, download the
required libraries and place them in the …\plugins
\servoy_jasperreports folder”

Where can I download the required libraries?

Suggestion: It would be helpful to have a direction in the file
“install.txt” where the required libraries can be downloaded.

Thanks
hp

As far as I know Jasper uses the poi libraries: http://poi.apache.org/