Let's Encrypt Firefox OCSP problem: Secure Connection Failed

Hi team

I am having trouble with one specific server that seems to be failing HTTPS websites only in Firefox (version 50.1.0)

When browsing a website for example, https: // myexampledomain .com (without spaces) on Firefox, I get the following error;

I have the same issue with ALL https domains on that server in Firefox - however all of the same https domains work fine in all other browsers (Chrome / IE10 / Opera).

My other servers seem to be fine and all sites on them are connecting to https in Firefox without an issue - so there is something going on with this particular server.

Server info:

• CENTOS 7.3 x86_64

• WHM 60.0 (build 28)

• Server Version: Apache/2.4.23 (Unix) OpenSSL/1.0.1e-fips

• Let's Encrypt

There are no problems noted in the Manage Auto SSL logs.

In httpd.conf :

Code:

SSLUseStapling on
SSLStaplingCache shmcb:/usr/local/apache/logs/stapling_cache_shmcb(256000)
SSLStaplingReturnResponderErrors off
SSLStaplingErrorCacheTimeout 60
SSLSessionCache shmcb:/usr/local/apache/logs/ssl_gcache_data_shmcb(1024000)

I notice the above httpd.conf entry is slightly different on my other server (which is running CentOs 6.8).

Please advise, thanks.

 

After some Googling, I came across a solution which I have tried it and it works for me:

However, I am concerned that turning SSLUseStapling OFF will have negative connotations. Could someone from cPanel please comment?

Thanks