the updating process completes but it says that some updates couldn't be found and has been ignored.
and apt-get install rygel just says cannot find rygel...

I've fixed the application manager. the problem was that in the instructions, they didn't tell me how to end the cat file. I searched it and found that after cat > file.txt i should press ctrl+d to save and end the file. i did that and the application manager worked. i tried to creat a cataloge for fatal manually but it couldn't refresh for some reason.