Couldn't register with the bootstrap Server

I just changed some code in my program and got this error:

Couldn't register com.yourcompany.XXX with the bootstrap server. Error: unknown error code.

This generally means that another instance of this process was already running or is hung in the debugger.Program received signal: “SIGABRT”.

I tried restoring my program to a version that worked, rebooted, restarted, empty caches and rebuild on versions that even worked before.

Any help would be appreciated.

I was able to recover from this by unplugging the iPad, powering it down and back up, clearing all XCode caches and targets, and doing a clean build. I'm running XCode 3.5.4 and iOS 4.2.1 Hope this helps someone. -Mike

UPDATE: Same problem running Xcode 4.3 and iOS5 - just power-cycle the device.

You might wish to kill all Simulator processes, that can cause this error as well.

Here's a one-liner to kill 'em all:

kill -9 `ps ax | grep Simulator | grep -v grep | awk '{print $1}'` 

Or more concise, like @brianegge mentions as a comment:

killall -9 Simulator

My solution was to restart the ipad, wait a while and try again.

If you get the hang when using the simulator, look at this thread: Strange Error When Testing Simulator

You may find this test of interest, as it will tell you ASAP if the only solution is to reboot now or not:

Open Terminal and run this command: ps -Ael | grep Z. If you get two entries, one "(clang)" and the other your app or company name, you're hosed - reboot.

If you are a developer, enter a short bug and tell Apple how absolutely annoying having to reboot is, and mention they can dup this bug to "rdar://10401934" .

I received the same problem, running an app on an iPhone from Xcode. The message that I was getting was the same as above:

Couldn't register xxx.com.company.appname with the bootstrap server. This generally means that another instance of this process was already running or is hung in the debugger.

I tried many things to fix the problem, in this order, all which failed:

• force quitting the app on the iPhone
• force quitting and then deleting the app the iPhone
• opening and closing the project
• cleaning the project
• restarting XCode

Eventually, I rebooted the iPhone and the problem went away, which leads me to think that the source of the problem is a hung process that Xcode cannot or will not kill. If I am able to reproduce exactly what I was doing during my debugging session to get this strange state I'll add another note here.