Apache: Invalid command 'SSLEngine', perhaps misspelled or defined by a module not included in the server configuration

Question

When configure apache2 virtual hosts for ssl/https connection, after adding configuration and enable the configuration with this command " a2ensite pm.university.com.conf " i got this error "Invalid command 'SSLEngine', perhaps misspelled or defined by a module not included in the server configuration". I will answer my own question.

Answer 1

It turned out I did enabled ssl module but i had to do it again and it works, here is the command:

sudo a2enmod ssl

Now restart apache like so service apache2 restart

no more error, FIXED!