nlcd: Process not entitled for this action (Network Link Conditioner)

Question

I've installed the Network Link Conditioner prefpane from the Hardware IO Tools for XCode October 2013 release (running 10.9 Mavericks).

I can enable the NLCD from preferences, but nothing seems to change. Additionally, the following is printed in my console:

nlcd[935]: Process not entitled for this action
System Preferences[1167]: connection to NLCd failed

I also tried to run nlcd directly from /usr/libexec, but it just prints the following:

<Notice>: Checkin with launchd failed, no port to listen on

I've seen a number of threads talking about this tool not working, but none with the same symptoms as this.

Answer 1

I removed the preference pane and installed it again to fix the problem.