This issue was originally marked as duplicate of issue 161726, that is already resolved. This issue is still valid, so this seems to be another issue, but it might be related.

Build: NetBeans IDE 6.7.1 (Build 200907230233)
VM: Java HotSpot(TM) Client VM, 11.2-b01, Java(TM) SE Runtime Environment, 1.6.0_12-b04
OS: Windows XP, 5.1, x86

User Comments:
GUEST: open NetBeans IDE

yoyozhu: when I open the IDE,it report this problem,though IDE also can use.

GUEST: Creo que el problema ocurrio porque trabaje con el netbeans mientras descargaba algo en el disco donde tengo instalado el sistema operativo y este se lleno. Cuando intente usar una conexion a Base de datos aparecio un error que decia q no se podia encontrar un driver para acceder a la Base de datos. Al reiniciar el netbeans aprrecio este error :S



Stacktrace: 
org.openide.filesystems.FSException: ???? ???? (org-netbeans-api-project-libraries/Libraries) ?????? EclipseLink-GlassFish-v3-Prelude.xml?
        at org.openide.filesystems.FSException.io(FSException.java:117)
        at org.openide.filesystems.MultiFileObject.createData(MultiFileObject.java:1077)
        at org.netbeans.modules.project.libraries.LibrariesStorage$1.run(LibrariesStorage.java:255)
        at org.openide.filesystems.EventControl.runAtomicAction(EventControl.java:120)
        at org.openide.filesystems.FileSystem.runAtomicAction(FileSystem.java:509)
        at org.netbeans.modules.project.libraries.LibrariesStorage.writeLibrary(LibrariesStorage.java:246)