An Apple spokesperson told Macworld USA that, “a small number of iMac users have indicated to us that the recent software update released by Apple may occasionally cause their iMac to crash, requiring a reboot.”
According to users, the computer is unstable, requiring a reboot to get it working again. Apple does not know the exact cause of the problem, although they are investigating it.
The Apple spokesperson indicates, “We are analyzing the root cause of this bug, and will publish a software update that will correct it as soon as possible, with the most likely occurrence later this month. We apologize for any inconvenience caused. “.