Failed to download HTTP access log from Web Dispatcher Administration

Hi experts,

I'm using SAP HANA SPS09 rev. 90. I first configured web dispatcher to log all HTTP accesses and granted sap.hana.xs.wdisp.admin::WebDispatcherAdmin to SYSTEM in SYSTEMDB. Thus I could log on to Web Dispatcher Administration and see the HTTP log as showed in the following screen shot.

When I clicked "Download", it returned "500 Internal Server Error" to me... However, I'm able to download the log file in SPS08. In SPS08, web dispatcher was not embedded into SAP HANA yet and the URL is http://<host>:<port>/sap/wdisp/admin/public/default.html instead of the new one.

It just seemed a bug to me. Is anyone able to download the HTTP access log file? Please tell me if you can. Thank you very much in advance.

Best regards,

Wenjun