Unable to connect to the dahsboard server with error

for me, it looks like there is a compression issue.

If you don't have already installed, you should install python-lesscpy (or how the package is called in your distribution, and switch off
COMPRESS_OFFLINE
(in settings.py)

Thanks Matthias for getting back. Unfortunately it didn't seem to help. Pls see the logs

----------------------- Install lesscpy -----
[root@wpc0016 tmp]# pip list | grep less
lesscpy (0.6)

------------------- Modified COMPRESS_OFFLINE to False ------

[root@wpc0016 usr]# cat ./share/openstack-dashboard/openstack_dashboard/settings.py | grep COMPRESS_OFFLINE
#COMPRESS_OFFLINE = True
COMPRESS_OFFLINE = False

------------------- Restarted httpd and openstack-dashboard --------

Not Found: /flavors/
[11/Dec/2013 00:57:13] "GET /flavors/ HTTP/1.1" 404 3385
Not Found: /static/dashboard/less/rhtheme.less
Not Found: /static/dashboard/js/588884c5a22a.js
Not Found: /static/dashboard/js/271a130e6a31.js
[11/Dec/2013 00:57:13] "GET /i18n/js/horizon/ HTTP/1.1" 200 2158
[11/Dec/2013 00:57:13] "GET /static/dashboard/less/rhtheme.less HTTP/1.1" 404 3385
[11/Dec/2013 00:57:13] "GET /static/dashboard/js/588884c5a22a.js HTTP/1.1" 404 3385
[11/Dec/2013 00:57:13] "GET /static/dashboard/js/271a130e6a31.js HTTP/1.1" 404 3385
Not Found: /static/dashboard/img/rhfavicon.ico
[11/Dec/2013 00:57:14] "GET /static/dashboard/img/rhfavicon.ico HTTP/1.1" 404 3385
[11/Dec/2013 00:57:35] "GET / HTTP/1.1" 302 0
Internal Server Error: /admin/
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/django/core/handlers/base.py", line 111, in get_response
    response = callback(request, *callback_args, **callback_kwargs)
  File "/usr/lib/python2.6/site-packages/horizon/decorators.py", line 38, in dec
    return view_func(request, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/horizon/decorators.py", line 86, in dec
    return view_func(request, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/horizon/decorators.py", line 54, in dec
    return view_func(request, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/horizon/decorators.py", line 38, in dec
    return view_func(request, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/horizon/decorators.py", line 86, in dec
    return view_func(request, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/django/views/generic/base.py", line 48, in view
    return self.dispatch(request, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/django/views/generic/base.py", line 69, in dispatch
    return handler(request, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/horizon/tables/views.py", line 155, in get
    handled = self.construct_tables()
  File "/usr/lib/python2.6/site-packages/horizon/tables/views.py", line 146, in construct_tables
    handled = self.handle_table(table)
  File "/usr/lib/python2.6/site-packages/horizon/tables/views.py", line 118, in handle_table
    data = self._get_data_dict()
  File "/usr/lib/python2.6/site-packages/horizon/tables/views.py", line 182, in _get_data_dict
    self._data = {self.table_class._meta.name: self.get_data()}
  File "/usr/share/openstack-dashboard/openstack_dashboard/dashboards/admin/overview/views.py", line 59, in get_data
    data = super(GlobalOverview, self).get_data()
  File "/usr/share/openstack-dashboard/openstack_dashboard/usage/views.py", line 28, in get_data
    self.usage.summarize(*self.usage.get_date_range())
  File "/usr/share/openstack-dashboard/openstack_dashboard/usage/base.py", line 193, in summarize
    _('Unable to retrieve usage information.'))
  File "/usr/share/openstack-dashboard/openstack_dashboard/usage/base.py", line 190, in summarize
    self.usage_list = self.get_usage_list(start, end)
  File "/usr/share/openstack-dashboard/openstack_dashboard/usage/base.py", line 231, in get_usage_list
    return api.nova.usage_list(self.request, start, end)
  File "/usr/share/openstack-dashboard/openstack_dashboard/api/nova.py", line 605, in usage_list
    novaclient(request).usage.list(start, end, True)]
  File "/usr/share/openstack-dashboard/openstack_dashboard/api/nova.py", line 361, in novaclient
    (request.user.token.id, base.url_for(request, 'compute')))
  File "/usr/share/openstack-dashboard/openstack_dashboard/api/base.py", line 260, in url_for
    request.user.services_region,
  File "/usr/lib/python2.6/site-packages/django/utils/functional.py", line 185, in inner
    return func(self._wrapped, *args)
AttributeError: 'User' object has no attribute 'services_region'
[11/Dec/2013 00:57:35] "GET /admin/ HTTP/1.1" 500 1666
Not Found: /static/dashboard/img/logo.png
[11/Dec/2013 00:57:35] "GET /static/dashboard/img/logo.png HTTP/1.1" 404 3385

Did you do an update/upgrade?
If yes, please clear your cookies for your horizon controller.

I think I remember this issue. The problem was, django_openstack_auth was outdated. For Havana, I'd use at least django_openstack_auth >= 1.1.0

updated to python-django-openstack-auth-1.1.2-1.el6.noarch seemed to help solving part of the problem. Thanks Matthias. The dashboard still can only display text, no graphics. Will continue digging-in further.

Please install latest version fpr this package python-django-openstack-auth. pip install django_openstack_auth. it work for me