Why is the Network Link Conditioner preference pane crashing as soon as I turn it on?

Just a quick note to say that I eventually stopped the crashing by manually copying these two files from another OS X machine and then manually starting the nlcd daemon (if you don't have another Mac, I posted my copies of those files here)

Copied these files:
/System/Library/LaunchDaemons/com.apple.NetworkLinkConditioner.plist
/usr/libexec/nlcd
Run these three commands:

sudo chown root /System/Library/LaunchDaemons/com.apple.NetworkLinkConditioner.plist      
sudo chmod 644 /System/Library/LaunchDaemons/com.apple.NetworkLinkConditioner.plist   
sudo launchctl load /System/Library/LaunchDaemons/com.apple.NetworkLinkConditioner.plist

After that the pref pane didn't unexpectedly exit when moving the switch to 'on'.

Taken from https://devforums.apple.com/message/645980#645980


I filed a bug report (#11891721) for this. I linked to odyth's answer in the report and this is their response.

Changing the nlcd file over to an older version makes it compatible with the preference pane, (as you did in this case). The current version of the prefpane works with the latest nlcd. We can not do anything about the older installs of nlcd or the prefpane that you have.

We are closing this bug since we are aware of the issue.

Please be sure to regularly check the seed notes and release notes for any updates that might affect this issue.  Again, thank you for taking the time to submit bugs. We sincerely appreciate your input.

So there's the official answer.


I had the same issue in Yosemite.

Tried with the files mentioned here, but it was still crashing.

Giving admin rights to my OS X user seemed to "solve" the issue. In other words, running the app as a "Standard" user seems to cause the crash for me.

Still it is not a nice solution, but maybe it helps some people or give insight for a better solution. :)