I see strange errors in your log. Did you copy an older/existing installation? Extraction doesn't work in this installation as the library is missing. You should fix the installation by doing the following steps.
Close JDownloader and delete Core.jar file and the folders update and tmp
and start JDownloader again
Path is C:\Users\USERNAME\AppData\Local\JDownloader 2.0
__________________
JD-Dev & Server-Admin
|