I run an issue search in a tracker with permissions on keywords restricted:

https://roundup-intern.intevation.de/flys/issue?%40search_text=&title=&%40columns=title&keyword=51&id=&%40columns=id&creation=&creator=&activity=&%40columns=activity&%40sort=activity&actor=&deadline=&%40columns=deadline&priority=&%40group=priority&disposition=&status=&%40columns=status&assignedto=&%40columns=assignedto&links=&group_customer=&group_partner=&group_internal=&%40pagesize=500&%40startwith=0&%40queryname=&%40old-queryname=&%40action=search

This works when logged in, but when opening the same URL in a browser
window where I'm not logged in, I get the following traceback with
Roundup e56047711df2 (April 2nd, 2014):

mod_wsgi (pid=15199): Exception occurred processing WSGI script
'/srv/roundup/example/roundup.wsgi'.
Traceback (most recent call last):
  File
"/home/intevation/roundup/current/lib/python/roundup/cgi/wsgi_handler.py",
line 66, in __call__
    client.main()
  File
"/home/intevation/roundup/current/lib/python/roundup/cgi/client.py",
line 376, in main
    self.inner_main()
  File
"/home/intevation/roundup/current/lib/python/roundup/cgi/client.py",
line 538, in inner_main
    self.renderFrontPage(message)
  File
"/home/intevation/roundup/current/lib/python/roundup/cgi/client.py",
line 1092, in renderFrontPage
    self.add_error_message(message)
  File
"/home/intevation/roundup/current/lib/python/roundup/cgi/client.py",
line 415, in add_error_message
    add_message(self._error_message, msg, escape)
  File
"/home/intevation/roundup/current/lib/python/roundup/cgi/client.py",
line 53, in add_message
    msg = cgi.escape(msg).replace('\\n', '<br />\\n')
  File "/usr/lib/python2.7/cgi.py", line 1035, in escape
    s = s.replace("&", "&amp;") # Must be done first!
AttributeError: 'Unauthorised' object has no attribute 'replace'

I would expect to see the error message.