The Apache refuses to start after creating the virtual host record for port 443. As a result, it throws an error “Invalid command ‘SSLEngine’ Error’”.

Here at Bobcares, we have seen several such apache related errors as part of our Server Management Services for web hosts and online service providers.

Today we’ll take a look at the causes for this error and see how to fix it.

What causes invalid command SSLEngine error to occur

Now let’s take a look at the causes for this error.

1. Most of the freshly installed Apache encounter this error message. Normally, when Apache starts it reads the configuration files and notices an unknown directive “SSLEngine”. This happens when the mod_ssl module installed/enabled in the configuration. Because this is responsible for creating and serving SSL connections.

2. If there are any configuration in /etc/httpd/conf or /etc/httpd/conf.d which you have forgotten then it will lead to this error.

How we fix invalid command SSLEngine error

Now let’s take a look at how our Support Engineers fix this error.

1. Install mod_ssl

In most of the cases, customers forget to install/enable mod_ssl in the configuration. So installing it will fix this error.

In order to enable this module on CentOS/RedHat Linux we run the following command:

sudo yum install mod_ssl

If you use Apache 2.4 version, the module name would be mod24_ssl.

To enable this module on a Debian-based distro run the following command:

sudo a2enmod ssl

After that, restart the Apache service by running the below command.

sudo apachectl restart

If the servers starts correctly, you can check the installation by running:

openssl s_client -connect yourdomain.com:443

2. Load the SSL module

In some cases, if you don’t load the SSL module then it will throw this error message.

So for that, you need to load the LoadModule directive somewhere in your apache configuration files.

For that, you can run the below command.

LoadModule ssl_module /usr/lib64/apache2-prefork/mod_ssl.so

3. Destroy forgotten configurations in the configurations file

In case, if you have forgotten configuration in /etc/httpd/conf or /etc/httpd/conf.d then find it and remove it. For that, run the below command.

grep SSL /etc/httpd/{conf,conf.d} -r

Or else you can simply install the SSL module.

This way you can fix this error message.

[Need any further assistance in fixing Apache errors? – We are here to help you.]

Conclusion

In short, this error occurs when Apache refuses to start after creating the virtual host record for port 443. Today, we saw different ways to fix this error.