Dear Markus,
Maybe problem connected with installation of language, there is must be next steps:
For Installation VehicleManager Languages, you need unzip file (languagebl.zip) to directory /components/com_vehiclemanager/language/
You will get next languages: Arabic, Brazilian, Portuguese, Danish, Dutch, English, French, German, Hungarian, Italian, Lithuanian, Norwegian, Portuguese, Romanian, Russian, Spanish, Turkish.
So, check this.
If you face any problems, please contact us through our contact form.
ordasoft.com/About-us/OrdaSoft.html
Thanks,
Taras
OrdaSoft team.