I replaced the database and getting the same errors about the fancy modules. No data at oldenburg!
And I still have to redo my pages. It gives a header error even that I replaced wt_webtrees in the code!
At present you will need to disable Fancy Image bar. I can see there is a bug in it. I will fix this as soon as I can.
The problem with “Descendants” is different. Your “Tudor” page runs normally. Only the “Oldenburg” one does not. That suggests there is a problem either with the data, or your server cannot handle the size of that page.