Vimbadmin unexpected error

Hi all

I recently installed the package mail on my server. Everything went well, but during my first connection to Vimbadmin, I came across this error message:

I checked all the configuration (postfix, dovecot) but nothing seems wrong to me. All vimbadmin mysql tables are present.
My configuration:
Debian 8
EasyEngine 3.7.4

Did anyone here have an idea?

Best regards,

٠̩̩̩Яا☪⚉ ḍḁ ㅒД╰ṽᴬ®Е☡

Hello everyone, I still can not solve this problem … no one has an idea?

Cheers,

٠̩̩̩Яا☪⚉ ḍḁ ㅒД╰ṽᴬ®Е☡