Arrowchat was unable to connect to the database

[RSchmidt]

Hi,
Arrow Chat is the install always following error message even though the database information is correct. The Forum and Arrow Chat running on a managed server on 1und1. Until today everything went. Then we made the update to the latest version and are no longer come in the admin area and the chat it was no longer displayed. Then we have reinstalled everything and now get this message: Arrowchat was unable to connect to the database with the provided information. Check your details and try again.

please help me
thank you