Deployment Problem Flex viewer

Dear All,
I have customised the flex viewer 2.6 and it is running on my own Computer having osperating system windows vista,i want to deploy the application.The server is the operating system 2008 server.When i deployed the application and run it it gives me the fallowing error.
TypeError:Error#1009 Cannot access a property or method with null object reference.
at mx.managers:System manager rawchildern
at mx.managers:systemchildernlist/removechildernlist0
at mx.managers.systemmanagers:preload_Preloaddonehandler
at flashevents:Eventdispatcher/dispatcheventfunction
at flash.events:eventdistpatcher/dispatchevent0
at mx.preloaders:Preloader/displayclasscompletehandler
at flashevents:Eventdispatcher/dispatcheventfunction
at flash.events:eventdistpatcher/dispatchevent0
at preload:CustomPreloader/drawProcess()(C:\Appname\src\CustomPreloader.as:95
at flash.utils:Timers/_timerDispatch()

so this was the complete error.Please help me.i am stuck here from last two days.

Thanks in advance