If you experience a,
"Domain is already processing an SSL request. Please allow it to finish before making other changes." error in DirectAdmin when trying to create a new LetsEncrypt SSL Certificate for your domain name, the solution is simple. Patience.
Chances are you have just registered your account or updated the DNS for the domain name very recently, and you have not actually previously attempted an SSL request, so the error message may be confusing. When a domain is added to our system, the server automatically generates an SSL Certificate for your domain and it will take some time usually before the process is completed for newly registered domains and domains with recent DNS updates, like those required to point them to your hosting account. As such, the error is simply stating that the server is processing an automated request for an SSL Certificate already. It's not been able to successfully complete this request yet, likely due to a recent change in your domain's DNS.
Most of the time this may take a couple of hours. Just because your domain name may resolve properly for you, does not mean that the servers LetsEncrypt uses for verification and their certificate issuing process has the same success.
If after a few hours pass and the error persists, please contact us and we can review the issue further.