Failed to send email (LanguageToFontInterface' not found)

Hello guys,

Could you please help me with this case? I’m not able to send email because it shows the following error:

Fatal error: Interface 'Mpdf \ Language \ LanguageToFontInterface' not found in /home/dokti.com.br/public/financeiro/vendor/mpdf/mpdf/src/Language/LanguageToFont.php on line 6 Call Stack: 0.0007 307464 1.

Do you know what it can be?

Thanks.
Ewerton Ventura