After Ajenti installation working site gives : 502 Bad Gateway nginx/1.6.0

I use Debain 7.5 Wheezy and my site was up and running. I installed Ajenti and since then I get 502 Bad Gateway error. When I click on Nginx on Ajenti (already removed Apache), I get the following error

[Errno 2] No such file or directory: '/etc/nginx/sites-available' Traceback (most recent call last): File "/usr/lib/pymodules/python2.7/ajenti/plugins/main/main.py", line 158, in handle_message self.ui.dispatch_event(update['uid'], update['event'], update['params']) File "/usr/lib/pymodules/python2.7/ajenti/ui/__init__.py", line 72, in dispatch_event self.root.dispatch_event(uid, event, params) File "/usr/lib/pymodules/python2.7/ajenti/ui/element.py", line 382, in dispatch_event if child.dispatch_event(uid, event, params): File "/usr/lib/pymodules/python2.7/ajenti/ui/element.py", line 378, in dispatch_event self.event(event, params) File "/usr/lib/pymodules/python2.7/ajenti/ui/element.py", line 402, in event getattr(self, 'on_%s' % self_event)(**(params or {})) File "/usr/lib/pymodules/python2.7/ajenti/plugins/main/main.py", line 376, in on_switch child.broadcast('on_page_load') File "/usr/lib/pymodules/python2.7/ajenti/ui/element.py", line 356, in broadcast getattr(self, method)(*args, **kwargs) File "/usr/lib/pymodules/python2.7/ajenti/plugins/webserver_common/api.py", line 144, in on_page_load self.refresh() File "/usr/lib/pymodules/python2.7/ajenti/plugins/webserver_common/api.py", line 154, in refresh self.hosts = [WebserverHost(self, self.hosts_dir, x) for x in self.hosts_dir.list_available()] File "/usr/lib/pymodules/python2.7/ajenti/plugins/webserver_common/api.py", line 25, in list_available return [x for x in sorted(os.listdir(self.dir_a)) if not os.path.isdir(os.path.join(self.dir_a, x))] OSError: [Errno 2] No such file or directory: '/etc/nginx/sites-available'

Please help. Thanks