Allen,
Try changing line 15 of the script to:
`tw = jmri.InstanceManager.getDefault(jmri.jmrit.throttle.ThrottleFrameManager.class).createThrottleWindow()`
This is due to the `.instance()` method being removed after 4.16 due to having been deprecated for quite some time.
Please let me know if this works as I'll then get this updated for the next release.
Best regards,
Matt H
Matthew Harris