Until yesterday I had no problems settings Let’s encrypt for any domain in my plesk panel. I’ve set up for about 30 but yesterday I had some problems. After waiting to Let’s Encrypt solved some problems with the server I started to get this messages with two new domains I’ve created in Plesk.
Error: Let’s Encrypt SSL certificate installation failed: Challenge marked as invalid. Details: Could not connect to domain.tld
It shows the same error in both domains. It’s strange because I didn’t change nothing since the last time unless the regular plesk updates. Help ?
Yes and it’s still not working. I asked here because no changes were made in the web server and everything worked fine until last weekend, but it’s possible that a plesk update have made some interference. I’ll try to search deeper.
My hosting provider said it was because of cloudflare, but I always could connect cloudflare with Let’s Encrypt for the already 30 domains I had. I’ve disabled cloudflare, try it again after waiting for some hours but with cloudflare disabled I have exactly the same error.
Yes, it means that the web server has not been correctly configured to use your certificate.
That certificate exists—it was issued successfully earlier today
but the web server somehow doesn't know that it should be using it.
I do believe that the original certificate issuance problems you had might have related to IPv6 because Let's Encrypt changed its practices just last week to always use IPv6 for validations when possible, and your site has both an IPv6 and an IPv4 address, so the default validation method would have changed recently. But the specific error that you see now ("RSA certificate [...] does NOT include an ID") is seemingly not a direct result of this change, because the certificate was successfully issued.
I agree with @ahaw021 that it's difficult for us to provide support for Plesk because so far there are no Plesk developers participating in this forum. You might be able to get better support on a Plesk-specific forum.