ClassNotFound Exception after update to nightly build

I am fairly new to this, so I'm hoping this is a simple solution.

I was running 3.8.0 but was running into the bug with Enable Contact List Group Sharing erroring out. The forums recommend updating to the latest nightly build.

So, I backed up my openfire directory, extracted the latest build and moved over my conf directory. I notice that in openfire/bin 'openfire' is not present, so I copied that from my backup as well. Now when I run ./openfire start then ./openfire status, I get the following error:

username@OpenfireBox:/opt/openfire/bin$ ./openfire status

Exception in thread "main" java.lang.NoClassDefFoundError: com/install4j/runtime/Launcher

Caused by: java.lang.ClassNotFoundException: com.install4j.runtime.Launcher

          at java.net.URLClassLoader$1.run(URLClassLoader.java:217)

          at java.security.AccessController.doPrivileged(Native Method)

          at java.net.URLClassLoader.findClass(URLClassLoader.java:205)

          at java.lang.ClassLoader.loadClass(ClassLoader.java:321)

          at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)

          at java.lang.ClassLoader.loadClass(ClassLoader.java:266)

Could not find the main class: com.install4j.runtime.Launcher. Program will exit

This seems to happen with three of the nightly builds I have run. Am I missing a step? Should I be using openfirectl now? Any help would be much appreciated.