I'm working on a client's website that was set up by someone else. It's hosted by Namecheap and we have access to cPanel.
The client is apparently receiving this email message twice a day (I've replaced their domain name with example.com):
[example.com] ⚠ example.com: The AutoSSL certificate renewal may cause a reduction of coverage on 2017-11-28 at 00:00:00 UTC
The “cPanel” AutoSSL provider could not renew the SSL certificate without a reduction of coverage because of the following problem:
The system failed to fetch the DCV (Domain Control Validation) file at
http://example.com/.well-known/pki-validation/(long string of letters and numbers).txtbecause of an error: The system failed to send an HTTP (Hypertext Transfer Protocol) “GET” request to
http://example.com/.well-known/pki-validation/(long string of letters and numbers).txtbecause of an error: Size of response body exceeds the maximum allowed of 16384
The domain “example.com” resolved to an IP address “(the IP address of our website)” that does not exist on this server.
I've been Googling around but there doesn't seem to be much about this. I looked through the "SSL/TLS Manager" section of cPanel but it appears to be blank. They've been using HTTP this whole time so it doesn't seem like it would be a case of an SSL certificate expiring.
What could be causing this kind of error and what kind of steps should I take next?