How to fix ERR_SSL_VERSION_OR_CIPHER_MISMATCH error on my website?

Hi, I’m unable to access my website today and see the following error message

ERR_SSL_VERSION_OR_CIPHER_MISMATCH.

Can access through admin but public facing side is down

My domain is from from 123-reg.

Site has been working fine up until today (I think.. could have been down over the weekend)

Any help would be much appreciated.

Actually I think it’s my router setup as it works fine on mobile.

It sounds like the ERR_SSL_OR_CIPHER_MISMATCH is showing because your public-facing site can’t establish a secure connection from certain networks. Since you mentioned it works on mobile, it might be your router or local network caching an old SSL configuration. Try clearing your browser cache, restarting your router, or checking from a different network. If the issue persists, contacting your domain provider (123-reg) to verify SSL settings can help.