To define the BX_DOL_URL_ROOT constant correctly, make sure the URL construction is complete and all parentheses are closed. In your current versions, there is a syntax error in the second variant due to a missing closing parenthesis.

Correct Version:

define('BX_DOL_URL_ROOT', ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') || (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https') || (!empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] == 'on') ? 'https' : 'http') . '://' . (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : 'www.exemple.com/') . '/');

Checking the scheme:

• (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on'): If the connection is secure (HTTPS).
• (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https'): If the forwarded protocol is HTTPS.
• (!empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] == 'on'): If SSL is on.

Constructing the scheme:

• If any of the above conditions are true, the scheme is https, otherwise http.

Constructing the host:

• isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : 'www.exemple.com': If HTTP_HOST is set, use it, otherwise use www.exemple.com as the default value.

Adding a trailing slash:

• . / '`' adds a trailing slash to the URL to ensure correct formatting.

Your fragment has a syntax error (missing closing parenthesis at the end) and should be corrected. However, it seems that you were right, I omitted to add this character "/" to the end of my domain name i wil check it out again. Big thank you.