Apple has released troubleshooting tips for an extremely annoying problem: Certain older Macs can suddenly freeze when installing macOS Big Sur. This makes the machine unusable, users can then neither forward nor backward – i.e. not even downgrade to an older macOS.

Computer goes on strike completely The bricking problem affects MacBook Pro machines that end 2013 as well as middle 2014 and over 13 inches large screens. With these it happens that the installer suddenly stops with the message that the update could not be “installed on this computer”. It can get even worse: Then the Mac starts up with a blank screen with a warning sign (crossed out circle) on it and nothing happens.

If one of the two variants occurs, Apple recommends a multi-stage procedure. First the computer must be switched off. To do this, press the power button for at least ten seconds. Then all external devices should be removed – screens, USB accessories and cards in the SDXC slot. Now the Mac is turned on. According to Apple it should then be able to be switched on again.

Standard Troubleshooting or Genius Bar Alternatively, Apple sets two standards Troubleshooting measures close at hand: Resetting the System Management Controller (SMC) and a reset of NVRAM or PRAM. If all three attempts have failed, affected users only have to visit an authorized repair shop or the Genius bar in an Apple store.

Apple’s support document suggests that the three recommended methods do not have to be the last word in wisdom. It says the article will be updated as soon as more information is available – this means that the company’s engineers are continuing to work on the problem. macOS Big Sur also has problems installing on other machines: With the brand new M1 Macs, it is currently not possible to restart the operating system. (bsc)