How do I fix libdispatch problem crashing Mac OS X apps?
- by david-ocallaghan
In the last day I have started having a lot of brokenness on my Mac (MacBook Air running Mac OS X 10.6.2 with all software updates).
Most noticably, iTunes no longer syncs with my iPhone. It fails with a crash dialog reporting "AppleMobileDeviceHelper quit unexpectedly" and an error dialog "iTunes was unable to load dataclass information from SyncServices. Reconnect or try again later."
I've attempted the fix at support.apple.com/kb/HT1747 but it failed.
I've also been having problems (at first seemingly unrelated) with the horrible Cisco VPN client, which started giving me this error:
Error 51: Unable to communicate with the VPN subsystem
I followed the steps at www.anders.com/cms/192/CiscoVPN/Error.51:.Unable.to.communicate.with.the.VPN.subsystem which don't seem to work for me, although I can connect if I use the command line with sudo :
sudo vpnclient connect MyProfile
I had a look in the Console app at the diagnostic messages and I noticed a pattern, that a number of apps were reporting "BUG IN CLIENT OF LIBDISPATCH". The affected programs are:
AppleMobileBackup
AppleMobileDeviceHelper
Safari Webpage Preview Fetcher
cvpnd (the Cisco VPN daemon)
Of these, only the last is non-Apple software!
The common text in the diagnostic messages is:
Exception Type: EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes: 0x0000000000000001, 0x0000000000000000
Crashed Thread: 1 Dispatch queue: com.apple.libdispatch-manager
Application Specific Information:
BUG IN CLIENT OF LIBDISPATCH: Do not close random Unix descriptors
I'm beginning to wonder if there's a permissions problem, or corruption of an important library, ...
I should note that I've rebooted several times and verified the disk permissions and the disk.
Any help would be great!