Since December 21st, I haven't been able to renew my LE certificate. The DirectAdmin logs show this information (see attachment). What could be the problem? I should add that everything has been working fine for 5 years, with no changes made. Please help, as the website doesn't have a certificate.
But, it looks like you were getting Let's Encrypt certs just fine. You got 8 different LE certs in the past week. Something must have gone wrong with how your server was configured. Or, maybe just wasn't reloaded after getting a fresh cert. Here is your recent history per https://crt.sh
Thank you for your answer, yes I changed it to Sectigo because I could no longer afford a longer break without SSL working on the website, but maybe there was actually a problem with relogging the hosting server.
Your cert from Sept was a wildcard cert. That would have required using a DNS Challenge. Did you change your DNS configuration since then? The error in your first post showed a failing DNS Challenge because your client could not pre-check your DNS entries within 5 minutes. That was not an error from Let's Encrypt. It was your system checking your DNS before submitting the request to LE.
All the certs issued in Dec were not wildcard. You still may have used a DNS Challenge to get those but to me they look like they probably used an HTTP Challenge.
Probably not. But, you got 8 certs so something worked.
Something must have changed. And, the error in your first post was for your system trying to reach your DNS servers.
Maybe something about your local DNS resolver has changed?
This "pre-check" just helps avoid sending requests to Let's Encrypt that probably won't work. That's a nice thing.
But, in this case your pre-check may be the thing that is broken. Can you disable this pre-check? Maybe Let's Encrypt won't have the same problem.
I don't know DirectAdmin very well. Maybe someone else here can give more advice or try asking on the DirectAdmin support forums.
I haven't seen any errors related to a Let's Encrypt failure. In fact, I saw 8 certs recently issued so this looks like your system is not configured properly.