It's a change that Windows 7 made to Java. Edit the mason.bat file and remove the word -server Sean On Jun 28, 2010, at 6:30 PM, Edith M wrote: > I am trying to run mason on windows but if i double click the > mason.bat file all > i get is a command prompt window that shows in a flash and then > disappers. If > i run it on Linux i dont get such poblems. Can anyone help me please.