The link to the threads in the widgets got a small problem, there is an "index.php" too much.
For example:
This is the link in the widgets:
http://localhost/xenforo/index.php?index.php?threads/archiv-der-gelehrten-vom-argonier-zum-saxhleel.1/
This would be correct:
http://localhost/xenforo/index.php?threads/archiv-der-gelehrten-vom-argonier-zum-saxhleel.1/
For example:
This is the link in the widgets:
http://localhost/xenforo/index.php?index.php?threads/archiv-der-gelehrten-vom-argonier-zum-saxhleel.1/
This would be correct:
http://localhost/xenforo/index.php?threads/archiv-der-gelehrten-vom-argonier-zum-saxhleel.1/