On my Moto E (second generation) when I connect to open WiFi on Opera Mini v25 I always get the following error: "Verification of server certificate failed. Please check the date setting on your device."
This does not happen on WiFi at home or at work or if I use 3G. I have seen others report this but some are from 2011 and others are because of a firewall or something like AdAway which I am not using. If I uninstall and try to reinstall, setup fails with the following error: "Connection blocked. Try switching network".
If I try to test connection in advanced it just loads for a while and then gives a blank screen.
I am using Android 6.0 and am in England and my service provider is Talk Mobile. I can upload screenshots if that would help.
This most likely means that public WiFi provider tries to redirect you to some login page or even intercept your encrypted connection. When you're on public WiFi try to load http://bbc.co.uk (not HTTPS!) with compression disabled or with another browser. You should be redirected to some login page. If you're not, then it probably means that for some reason Opera Mini is blocked by this public WiFi operator and you should contact with them.
Thanks, I have already signed in at this point through Android's WiFi sign in, Chrome will work then for example. I'll try removing the "s" next time and see what happens though. This happens on many different providers (eg. airports, trains, cafes), I'd be surprised if they blocked Opera Mini...