An unrecoverable error occurred.

The problem Link to heading

I could not create new content on Drupal 7. The error message was: An unrecoverable error occurred. The uploaded file likely exceeded the maximum file size (2 MB) that this server supports.

The solution Link to heading

The mod_rewrite Apache 2 module was not enabled.

It can be enabled using the following command (Debian 7):

a2enmod rewrite```

You then have to restart Apache:

```bash
service apache2 restart```

You many also need to change file `/etc/apache2/sites-enabled/000-default`.
Change `AllowOverride None` to `AllowOverride All` (2 times) and you are done!

(*Do not forget to restart Apache*)