Check apache2 enabled modules:
$ sudo apache2ctl -M Loaded Modules: core_module (static) log_config_module (static) logio_module (static) mpm_prefork_module (static) ... |
mod_rewrite (rewrite_module usually manipulated in .htaccess) and ssl (for HTTPS) for examples aren’t enabled by default in Ubuntu’ installation of apache2.
Enable one or more of them via:
$ sudo a2enmod |