When I want to install a free Let's Encrypt certificate it gives me the error below. What is the cause and what can I do? I didn't have that problem before. I can no longer install any certificates from a newly added site.
"Verification failed, domain name resolution error or verification URL cannot be accessed!
Verify domain name: domainx.ro
Verify URL: Click to view
Verify content: qu1ulqP2TP8wVcyrXhfpZ0tAjDRkaKmXalyKt83PV1o
Error code: Invalid response from https://domainx.ro/.well-known/acme-challenge/qu1ulqP2TP8wVcyrXhfpZ0tAjDRkaKmXalyKt83PV1o [5,189,170,444]: 500
Verify results: Verify failed"