1. Enable "mod_rewrite".

To enable mod_rewrite, run these commands in a terminal:

sudo a2enmod rewrite
sudo service apache2 restart

2. If the previous step did not help, try to enable .htaccess support.

Add/edit the server configuration settings /etc/apache2/sites-available/ESPO_VIRTUAL_HOST.conf or /etc/apache2/apache2.conf (or /etc/httpd/conf/httpd.conf):

<Directory /PATH_TO_ESPO/>
 AllowOverride All
</Directory>

Afterwards run this command in a terminal:

sudo service apache2 restart

3. If the previous step did not help, try to add the RewriteBase path.

Open a file {API_PATH}.htaccess and replace the following line:

# RewriteBase /

To

RewriteBase {ESPO_PATH}{API_PATH}

For more information please visit the guideline Apache server configuration for EspoCRM.