NPE in VirtualJarInputStream

Caused by: java.lang.NullPointerException
at org.jboss.vfs.VirtualJarInputStream.read(VirtualJarInputStream.java:149)
at org.eclipse.osgi.internal.baseadaptor.AdaptorUtil.readFile(AdaptorUtil.java:75)
at org.eclipse.osgi.internal.baseadaptor.BundleInstall.begin(BundleInstall.java:77)
at org.eclipse.osgi.framework.internal.core.Framework.installWorkerPrivileged(Framework.java:922)

In a Deployer I get a bundle location as String from the configuration.
I pass the String on to a 3rd party library (i.e. Equinox)

Equinox does
URLConnection urlcon = new URL(location).openConnection()
urlcon.openStream();