"Make Mailing Labels" not working for Bosnia language
It's because it's using Helvetica font which doesn't have unicode characters - if you can use Deja Vu Sans or another font that has unicode it should work.

IGNORE rest of answer below. As per comments Cesar found that under Administer - Communications - Label Formats you can change the font in there.



You can try to hack CRM/Utils/PDF/Label.php to hardcode the font: https://github.com/civicrm/civicrm-core/blob/5.20.3/CRM/Utils/PDF/Label.php#L180

I'm not sure the right spelling to get the font. If you look in vendor/tecnickcom/tcpdf/fonts/dejavusans.php it seems like it might be DejaVuSans, without spaces.

You can also try this instead:


Copy vendor/tecnickcom/tcpdf/config/tcpdf_config.php somewhere, e.g.
/usr/local/tcpdf/tcpdf_config.php
Edit the line inside it for PDF_FONT_NAME_MAIN so it reads define('PDF_FONT_NAME_MAIN', 'dejavusans'); (again I'm not sure of the exact spelling).
In civicrm.settings.php add these lines:


define('K_TCPDF_EXTERNAL_CONFIG', TRUE);
require_once('/usr/local/tcpdf/tcpdf_config.php');