我知道这个问题已经被问过好几次了，但我需要一些具体的帮助，因为我一直在听取其他几个线程的建议，但到目前为止没有任何效果。
我正在尝试在 Ubuntu 14.04 中使用 更新我的 SSL 证书certbot-auto renew，并且我正在运行 Apache2 服务器和 nginx。我得到以下输出certbot-auto renew：
root@PostgreSQLServer:/# sudo certbot-auto renew
Saving debug log to /var/log/letsencrypt/letsencrypt.log
-------------------------------------------------------------------------------
Processing /etc/letsencrypt/renewal/my-domain.com.conf
-------------------------------------------------------------------------------
Cert is due for renewal, auto-renewing...
Renewing an existing certificate
Performing the following challenges:
http-01 challenge for my-domain.com
Waiting for verification...
Cleaning up challenges
Attempting to renew cert from /etc/letsencrypt/renewal/my-domain.com.conf produced an unexpected error: Failed authorization procedure. my-domain.com (http-01): urn:acme:error:unauthorized :: The client lacks sufficient authorization :: Invalid response from http://my-domain.com/.well-known/acme-challenge/ailNmgZADpb4QBipKM57sOi9w3PwNkwBwVFiRYs7i40: "<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p". Skipping.
All renewal attempts failed. The following certs could not be renewed:
/etc/letsencrypt/live/my-domain.com/fullchain.pem (failure)
1 renew failure(s), 0 parse failure(s)
IMPORTANT NOTES:
- The following errors were reported by the server:
Domain: my-domain.com
Type: unauthorized
Detail: Invalid response from
http://my-domain.com/.well-known/acme-challenge/ailNmgZADpb4QBipKM57sOi9w3PwNkwBwVFiRYs7i40:
"<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p"
To fix these errors, please make sure that your domain name was
entered correctly and the DNS A record(s) for that domain
contain(s) the right IP address.
我确保.well-known文件夹存在/var/www/my-domain.com/public_html，当我http://my-domain.com/.well-known/在浏览器中导航到时，我能够看到该目录的内容。我还在其中添加了一个acme-challenge文件夹.well-known并包含了一个test.txt用于测试的文件；我能够在浏览器中访问目录和文本文件。
我发现acme-challenge运行命令时没有创建文件夹，certbot-auto所以这似乎是权限问题。我certbot-auto以 root 身份运行，但也授予www-data用户对.well-knownandacme-challenge文件夹的写入权限（root 和 www-data 用户正在运行 apache2 和 nginx 进程）。
即使在授予该写权限后，我仍然会收到上面详述的 404 错误。
我还运行了一个自动证书更新过程，crontab并且我将输出记录到本地文件中。在该日志文件中，我看到续订请求似乎工作正常，直到certbot-auto从 0.9.3 升级到 0.10.1。以下是升级发生时日志文件中的示例：
-------------------------------------------------------------------------------
Processing /etc/letsencrypt/renewal/offensively-bad.com.conf
-------------------------------------------------------------------------------
The following certs are not due for renewal yet:
/etc/letsencrypt/live/offensively-bad.com/fullchain.pem (skipped)
No renewals were attempted.
-------------------------------------------------------------------------------
Processing /etc/letsencrypt/renewal/offensively-bad.com.conf
-------------------------------------------------------------------------------
The following certs are not due for renewal yet:
/etc/letsencrypt/live/offensively-bad.com/fullchain.pem (skipped)
No renewals were attempted.
Upgrading certbot-auto 0.9.3 to 0.10.1...
Replacing certbot-auto...
Creating virtual environment...
Installing Python packages...
Installation succeeded.
-------------------------------------------------------------------------------
Processing /etc/letsencrypt/renewal/offensively-bad.com.conf
-------------------------------------------------------------------------------
All renewal attempts failed. The following certs could not be renewed:
/etc/letsencrypt/live/offensively-bad.com/fullchain.pem (failure)
IMPORTANT NOTES:
- The following errors were reported by the server:
Domain: offensively-bad.com
Type: unauthorized
Detail: Invalid response from
http://offensively-bad.com/.well-known/acme-challenge/tkSc8l-r1XVPIF5TosTbEXiYMa8sQnoXEjAEgAwRoqI:
"<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p"
To fix these errors, please make sure that your domain name was
entered correctly and the DNS A record(s) for that domain
contain(s) the right IP address.
您可以看到升级后，该过程开始失败并显示 404 消息。
我已经尝试了所有可以在网上找到的建议并且完全被难住了，所以任何帮助都将不胜感激。提前致谢！