Oh that is quite bad…
Have you tried with Firefox V52.9.0esr?
It does still work for me…
Or maybe it is also a OS thing (if not only with most recent browser versions).
What OS (Windows, Linux, etc.) do you run?
Is it the same same for all of them?
I can’t imagine it being on Memrise’s end. I’ve no problems here (Chromium on Linux, but checked with Firefox too). According to my browser, Memrise’s SSL certificate’s just fine. I do sometimes get Chromium’s equivalent error message, but for other, perhaps-questionable-looking sites. Can’t imagine why you’d get it for Memrise.
Is your version of Firefox out of date? Sometimes, weird things happen when it’s too many versions behind.
If it’s not too much trouble, please post here when you work out what the problem is. I’d be interested to know if it’s just a setting’s problem in your browser or if there’s some more disquieting reason.
I switched today DNS and the problem resolved itself.
Thanks for the comments guys.