I happened to launch Activity Monitor the other day. Upon looking over the list of processes, I was surprised to see two items in red, with the phrase “Not Responding” appended to each name. The two processes were UserEventAgent and coreadudiod.
This was something I had never seen before. And it was the sort of something I did not want to see. Even though the response failures were not causing any symptoms that I had noticed, I was concerned that I now had a serious, heretofore undetected problem.
Unfortunately, before I could even select either of these items, in the hope of learning more about what was going on, the two items vanished from the list. A few seconds later, the mysterious processes returned—still in red and still not responding. This game of cat-and-mouse continued until I gave up and hoofed it over to my Web browser to search for answers.
It turns out that the proximate cause of the problem was my recent installation of Hear, an audio processing program from JoeSoft. The fix is simple. Just install the recently released 1.0.2 update, which specifically addresses this issue (as noted on the downloads page for Hear at Apple’s Web site.
However, the true cause of the problem is not Hear, but Leopard (Mac OS X 10.5); Hear is just the trigger. The error message is also apparently a false alarm. According to my sources, even though Activity Monitor is claiming that the processes are not responding, Activity Monitor is wrong—everything is working just fine. This is why, as was the case for me, you likely won’t notice any symptoms associated with this quasi-bug. The Hear update simply found a way to prevent Activity Monitor from listing the false alarm.
Consistent with this, the UserEventAgent “non-response” may result from a variety of other software. UserEventAgent is a background process, responsible for loading plug-ins such as those located in the /System/Library/UserEventPlugins folder. One of the items in this folder is Apple’s BluetoothUserAgent-Plugin. Many users who have been bitten by this “not responding” bug report that removing the Bluetooth item from the folder (and restarting the Mac) eliminates the symptom. Certain other audio plug-ins (from Pro Tools and Digidesign) have also been cited as triggering the symptom.
Of course, removing the Bluetooth plug-in may cause other problems if you use Bluetooth with your Mac. However, as the message is a false alarm, you don’t have to remove the item. Instead, just ignore the Activity Monitor listing.
A few users have claimed that the supposedly not-responding process uses up an inordinate percentage of the Mac’s CPU, possibly slowing down the Mac’s responsiveness, but most others (including myself) have not seen that.
Still, it would be preferable for these messages, real or false, to go away entirely. In the end, a complete and permanent fix will require an update to Mac OS X.