Navision 2015 Fieldcaptions in wrong Language

We made a Server-Change at a Customer.
We didnt make any changes in the DB.
After the Change we set all Language and Region Settings to Austria.
Now Everything in the RTC is in Austrian Language except FIELDCAPTIONS.
For Example on the Sales Order Report individual Captions are German(Austria) but SalesHeader.FIELDCAPTION("No.") is still English.

Anyone else experienced this before or know how to fix this?

Thanks in advance