Call to undefined method modSRFilterHelper::getFilterByReviewScore()

Hi,
I was checking my site with some online page tester And I've discovered an issue.
On this page www.gmonamour.it/appartamenti-affitto-casa-vacanze-grottammare
there is this url www.gmonamour.it/index.php?option=com_so...k=hub.updateFilter&&
with error 500; this error is reported by the page tester.
If you call that url by a browser you have: Call to undefined method modSRFilterHelper::getFilterByReviewScore()
Please could you check and give me a solution to fix that?
Thanks a lot
Best regards
PS:I have some overrides but I tryed to disabled them. but the result is the same, the same error.

Hi,

That URL is called by AJAX and it is not supposed to be run directly from the browser.

If you can replicate this issue from your website UI, please provide us more details, we will check it for you.

Regards,

Hi,
no, from the website you can't see the issue.
It is reported by the site tester only. Here some:
www.webpagetest.org/result/180219_K5_20e...rmance_optimization/ -> see details
gtmetrix.com/reports/www.gmonamour.it/lxdfrRS4 -> see waterfall
tools.pingdom.com/#!/cXN1k5/https://www....-vacanze-grottammare -> see response code and files request
Best regards

Hi,
where are you?
any news?