Cannot install Xcode 10 Network Link Conditioner in macOS Mojave

I ended up manually copying the .prefPane file to:

/Library/PreferencePanes

After restarting Settings.app, it finally appeared on the list and worked perfectly.

As Martijn Scheffer stated in this comment, the reason for the pane not appearing in System Preferences is that the installer incorrectly puts the file to ~/Library/PreferencePanes instead of /Library/PreferencePanes.

Download in https://developer.apple.com/download/more/ Additional Tools for Xcode 10.1

In case the NLC is freezing when turning it on in the preferences it's important to note that it has to run as admin.

With the following command the preference app from MacOS can be started as admin:

sudo /Applications/System\ Preferences.app/Contents/MacOS/System\ Preferences

See here: https://stackoverflow.com/a/36445625/4417912

+1 to brainray, what worked for me was:

1. Download new Network Link Conditioner
2. Replace the old one in /Library/PreferencePanes
3. Open Network Link Conditioner directly from /Library/PreferencePanes

It now appears in my Settings app

Network Link Conditioner is already installed but you can't see it on the Settings App. This worked for me:

1. Press Command + Space to open spotlight
2. Search for Network Link Conditioner
3. It will appear on the result, click on it and it will open Settings app.
4. Network Link Conditioner is now visible in the Settings App. Open it from the Settings app.

Hope this helps!