LINK has stopped working.

Attaching my list of running processes, just in case it's useful.

@Kelly > You noted the laptop has the wireless enabled; have you tried with the wireless disabled and verified there are no other active / enabled networking items (eg. Blackberry connection). Also, please try with a local audio file rather than a network-based one.

Yep. Tried a local file. Tried directly connecting to the CDJ. I even shut down my network to purge the DHCP reservations and tried wired connections to the CDJ. It worked great for over a year, then suddenly *poof*. I try to establish the link, and it won't.

The only thing I can think of that changed was I updated iTunes a few weeks prior.

Wait. I updated more than iTunes at the end of April. I got tired of looking at those update notices; so, I updated iTunes to 12.1.2, Application Loader (whatever that is) to 3.0, iMovie to 10.0.8, Keynote to 6.5.3, Pages to 5.5.3, Numbers to 3.5.3, Remote Desktop Client to 3.8.2 v1.1 and a Security Update 2015-004.

Here's the info on that security update, https://support.apple.com/en-us/HT204659.

@Kelly > Is the CDJ icon shown when enabling the LINK button displayed on rekordbox? 

Can you browse the Collection of rekordbox from CDJ when LINK is ON?

Would you please provide us with Activity Monitor log when LINK is enabled with rekordbox running.

Sorry for the delay. Here's the activity list while LINK is "running."

Is a port being blocked?

Oh. I am all about getting to the bottom of this.

OK. I've confirmed for myself the following:

1. My Mac's firewall is blocking something.
2. My CDJ2000 Nexus is listening on TCP ports 1051, 12523, and 50003.
3. Launching Rekordbox from the console, it seems to be testing multiple ports, none of which are the three listed above. (See attached transcript.)
4. The following apps are listed in my firewall's white list: Rekordbox 3, PSvLinkSysMgr.app, and PSvNFSd.app (the last two are confirmed to be within the Rekordbox 3 package contents.)
5. My Mac will always ask if Rekordbox is allowed to accept incoming connections.
6. Sometimes it asks if PSvLinkSysMgr is allowed. If it asks, and I allow incoming connections, LINK will work. Currently, it seems to only ask if the firewall is turned off. Obviously, this wasn't always the behavior.

So. How do we get Rekordbox 3 and PSvLinkSysMgr through the firewall? Turning the firewall off is not an acceptable solution.

@Kelly > Try this:

That didn't work. I'm in the middle of testing permutations with the firewall off to see what works. Not having any luck so far.

OK. I honestly can't figure out what's going on. It's being extremely inconsistent. After a restart (of my laptop) I got LINK to work wired, wi-fi, and direct with the firewall turned off. (BTW, there are features available with a wired connection that I didn't know existed.) Anyway... so, I turn on the firewall expecting things to go haywire. Surprise! LINK worked over a wired connection with the FWall on. Supplies! LINK worked over wi-fi with the FWall on. WTH!

The only thing that has been consistent in this whole adventure is, with the FWall on, if it asks permission for PSvLinkSysMgr, LINK will work. Otherwise, it won't. Whatever edb_streamd is, it never, ever asks permission for it.

Weird ... so things are working for you now in a way you're happy with?