Your executable for the graphviz front end (eg dot on unix/inux or dot.exe on windows) is not set properly in your xwiki configurations so when it tries to run the program you get an error. 3 things. 1) Do you have graphviz installed? See http://www.graphviz.org/Download..php 2) Do you have the following line in your xwiki.cfg to enable the plugin. xwiki.plugins=com.xpn.xwiki.plugin.calendar.CalendarPlugin, com.xpn.xwiki.plugin.feed.FeedPlugin,com.xpn.xwiki.plugin.ldap.LDAPPlugin,com.xpn.xwiki.plugin.google.GooglePlugin,com.xpn.xwiki.plugin.alexa.Alexa,com.xpn.xwiki.plugin.mail.MailPlugin,com.xpn.xwiki.plugin.graphviz.GraphVizPlugin 3) There is normally a line that points to the executable like: xwiki.plugin.graphviz.dotpath=c:/Program Files/ATT/GraphViz/bin/dot.exe xwiki.plugin.graphviz.neatopath=c:/Program Files/ATT/GraphViz/bin/neato.exe So if you adjust it to match yours you should be fine. Cheers, Mark On Wed, 2006-03-08 at 10:02 +0800, SIM SOON HUAT, CTSID wrote: -- Mark Robinson Regional Clarity Project Manager (HK & AU) TNT Freight Managment (Australia) Limited TNT Freight Managment (Hong Kong) Limited 3rd floor, Two Harbourfront, 18-22 Tak Fung Street, Hung Hom, Kowloon, Hong Kong Tel: +852 26213688 (ext. 374) Mob: +852 90335711 Em : mark.robinson(a)hk.tntfreight.com Web: http://www.tntfreight.com