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/ on line 6 Call Stack: 0.0007 307464 1.

Do you know what it can be?

Ewerton Ventura