[Ultimate Social Media Plus] Plugin’s configuration page does not load

I have the same problem with the Ultimate Social Media plugins (both Icons and Plus) as described here:
https://www.ads-software.com/support/topic/spinning-circle-never-goes-away-plug-controls-wont-load/

So I see only a perpetually spinning circle when I am trying to access the settings page. Proposed solutions do not work. AdBlock is off, PHP, CURL are checked.