[JAVA3D] please help me. Its urgent

[Borja Marcos Su�rez]

What does it mean this error? My program worked fine until yesterday and the only thing I have done is installing sdk, jre and Java 3D because I have formatted the computer.     java.lang.NullPointerException  at javax.media.j3d.View.assignViewId(View.java:3075)  at javax.media.j3d.MasterControl.registerView(MasterControl.java:1639)  at javax.media.j3d.MasterControl.viewActivate(MasterControl.java:2166)  at javax.media.j3d.MasterControl.handlePendingRequest(MasterControl.java:2623)  at javax.media.j3d.MasterControl.doWork(MasterControl.java:2565)  at javax.media.j3d.MasterControlThread.run(MasterControlThread.java:28)   Thanks in advance.     ------- Borja