Problems with addin Files to the library

Hi All

I just installed the serviio media server to my qnap nas ts 269-L

It is really a good application, because with this media server i was able to see my movies on the sony bravia tv in my room (in the living room im streaming with the ps3, also worked fine)

But now I got problem, when I add my folders to the Library (working on the web console) it is only adding 180 movies, but in this folder there are a lot more movies. Also I tried to add my folder "Serien".

So I choose "Add Local" and then choose my folder (/Qmultimedia/Serien). When I try to choose this folder, I always receive the message:
Error encountered:
TypeError: Unable to get value of the property
"getElementsByTagName': object is null or undefined

I do not exactly understand what the problem is. In this folder "Serien" I save all my series, so there are a lot of sub folders. Is it possible that this is the problem?

Or do I have to change some of my settings in the webconsole?

I would be thankfull for every help I get. At least, sorry for my english, as a swiss guy im not really used to write a lot of english.

greetings