TLS set to min 1.2 on Plesk Host. Will this cause issues?

Hi Folks,
I have set minimum TLS protocol on my MediaTemple Grid Plesk server to TLS 1.2. Then also disabled all the rest. I wonder if I have overdone it as when I try to go through WP-Admin for wordpress I am getting intermittant 521 errors. I also checked my cloudflare firewall event logs and I have a few “Browser integrity check” block actions. Has anyone experienced these kind of issues?

Many thanks!

Also, I have installed the web application firewall (ModSecurity) and set to “On” (which blocks rather than logs) - and the rule set was set to OWASP ModSecurity which is hella strict. So maybe that might be the issue rather. Thx!

Let’s start with the domain :wink:

Oh ha, sorry. Its lol!

Loads generally fine for me. You get the 521 only in the administrative area? How often? Maybe try to disable one security feature after the other to find out which might block it.

Alternatively it simply could be your server which becomes unreachable at times. 521s are covered at Community Tip - Fixing Error 521: Web server is down.

TLS 1.2 on the origin should not be an issue though.

Okay thank you - Yes, its very intermittent. I added a whole bunch of security protocols to the Plesk server so going through those now and adding Cloudflare IPs etc etc. Thanks for your advice!

If you don’t have all Cloudflare IPs whitelisted yet that could easily be the explanation.

Thank you! BTW, is there a little notification / uptime checker that can be activated in Cloudflare so that I may be notified the next time the connection to the original host fails?

There’s and

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