There is no data in the database called WT_WEBTREES.
This is NOT a database problem. It is a FILE problem.
One other thought though. You had problems before with some bad text in your Danish language file. Have you cleared your kiwitrees cache lately? Might be worth trying. If that doesn’t help you might have to look in your language file.
The only other thing I can suggest is to send me FTP access so I can look at the files you have (Tomorrow).