I am setting up Apache server among other things on GNU/Linux Debian box. It seems like all is configured and and should be ready to go. I have restarted apache2 service and getting this error message:
Invalid command ‘SSLEngine’, perhaps misspelled or defined by a module not included
I have checked my configuration file for the site and see that SSLEngine is set ON. However I completely forgot to run and enable the ssl mode on the web server 🙂
sudo a2enmod ssl service apache2 restart
Now all should work as expected unless you have made a mistake in your configuration file. This resolved completely this issue for me.