It says that there's no certificate or something like that. I've made an exception but I still get a black GOG icon and have no way to access my account!!

I'm on iPhone right now.

Anyone with similar problem?

Thank you in advance <3

Could you write down the exact error message? That tends to be helpful for giving suggestions for how to fix.

Which Firefox version are you using? (Check Help -> About Firefox)
Are you at home, using your own internet connection, or at work / in a coffeeshop or a similar place where there could be a 'security' product trying to man-in-the-middle your connection in order to sniff its contents?

My Firefoxes (both stable - 55.0.2 - and beta - 56.0b3) work just fine, and have a valid certificate for *.gog.com issued by Symantec valid from 2017-01-31 through 2018-02-01 with SHA256 fingerprint starting with 3F:3B (gog eats my posts when I try to put in the entire fingerprint) >.<

Downloaded Firefox on my iPhone and logged into gog on it. Works fine here

My guess is that you have an add-on/extension that mistakenly blocks the site. Maybe even some Antivirus on the phone?

I use Firefox and every month or so I get blocked from here for about five minutes. I'm not really worried about it because I spend too much time here as is, and also I'm afraid I might make the problem worse by trying to make it better.

Too many fake newz on here, I guess. ;)

Or maybe when you were sleeping, your wallet hacked Firefox to make sure he doesn't get raped through GOGs promos ;)

Took me 4 hours to figure this out!

Yes that was The System Clock; I always forget to set it back on!

I want the time to be set manually but I keep forgetting to set clock/date, right after mobo reset.

Sorry and thank you everyone! <3

Actually there does appear to be an issue with the SSL certificate:

https://www.ssllabs.com/ssltest/analyze.html?d=www.gog.com

The icon you see in your browser's USL bar just makes sure the certificate is current and valid for the site you're looking at.