Statistics inaccessible

I'm newbie with Plesk.
I've a Onyx 17.0.17 with a Virtual Server.
I'm not able to show the Statistic Panel.
With a click in the Website and Domain / MyDomain / Web Statistic I load the page:
https://MyDomain/plesk-stat/webstat/
but this page is always in timeout.

Thanks in advance for any advice.