Good evening, I have a party with the magento 1.9.0 in the filters of the store
when you press anti filter, unfortunately the whole site crashes
and no other windows opens
look at this page >>>>> https://bestsmart.gr/--2603/.html
if, for example, you press a filter on your left
the whole site is stuck
I tried to click on the left navigation but nothing broke but the no action happened.
But I noticed a few issues, you are loading the unsecure content over the https content.
The filter request is blocked.
Please see the attached screenshots.
Try to make those urls secure then check.