While restoring the back-up plug-in hangs, giving me a 'ClassNotFoundException' (FakeObject) after deleting the entire hudson home directory

at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: org.jvnet.hudson.plugins.backup.uti
ls.FakeObject
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
... 2 more

Tested on two windows machines with the same result.