Why am I getting "Error dbus : Failed to connect to socket /tmp/dbus-XXXXX: Connection refused"

Issue

• When trying to start graphical applications using remote connections, these always fail with the following messages :

Error starting Virtual Machine Manager: Failed to contact configuration server; some possible causes are that you need
to enable TCP/IP networking for ORBit, or you have stale NFS locks due to a system crash. See:
http://projects.gnome.org/gconf/ for information. 
(Details - 1: Failed to get connection to session: Failed to connect to socket /tmp/dbus-DZ3EhjiPEV: Connection refused)  

Details:  

Traceback (most recent call last):  
File "/usr/share/virt-manager/virt-manager.py", line 455, in <module>  
main()  
File "/usr/share/virt-manager/virt-manager.py", line 390, in main  
icon_dir, data_dir)  
File "/usr/share/virt-manager/virtManager/config.py", line 99, in __init\__  
gconf.CLIENT_PRELOAD_NONE)  
GError: Failed to contact configuration server; some possible causes are that you need to enable TCP/IP networking for ORBit, or you have stale NFS locks due to a system crash. See http://projects.gnome.org/gconf/ for information. (Details - 1: Failed to get connection to session: Failed to connect to socket /tmp/dbus-DZ3EhjiPEV: Connection refused)