I try to run AWN, but the terminal gave me these errors:

Code:
gconfd-2(9669): Bewerking niet toegestaan
gconfd-2(10621): Bewerking niet toegestaan
gconfd-2(11155): Bewerking niet toegestaan
Traceback (most recent call last):
  File "/usr/bin/awn-manager", line 220, in <module>
    awnmanager = AwnManager()
  File "/usr/bin/awn-manager", line 136, in __init__
    self.prefManager = awnPreferences(self.wTree)
  File "/usr/share/avant-window-navigator/awn-manager/awnPreferences.py", line 100, in __init__
    self.setup_chooser(defs.APP, defs.ACTIVE_PNG, self.wTree.get_widget("activefilechooser"))
  File "/usr/share/avant-window-navigator/awn-manager/awnPreferences.py", line 254, in setup_chooser
    self.load_chooser(group, key, chooser)
  File "/usr/share/avant-window-navigator/awn-manager/awnPreferences.py", line 268, in load_chooser
    raise "\nKey: [%s]%s isn't set.\nRestarting AWN usually solves this issue\n" % (group, key)
TypeError: exceptions must be classes or instances, not str
How Can I solve it?