The MacBook Air EFI had its version of 2.9 update released the previous week in order to address some issues found in the mid-2011 hardware. The latter is said to run OS X 10.9.2 and higher.
Users have reported that the mid-2011 model had shown a long delay with its waking up and sleeping mode. Others have confirmed a few instances wherein the laptop's fans would surprisingly shift into the high gear mode.
While the update is meant to solve these issues, it seems like it has its own issues to solve. Based on the reports that have been gathered at Apple's official Support forums, the update had actually caused the MacBook Air to crash.
The exact cause on why the update has been giving problems is not yet known. It seemed to have a bug that disable users from installing it and worse, causes their system to crash.
One user was reported to have brought his machine to the Apple Store Genius Bar. The machine was treated with a "soft" System Management Controller (SMC) reset as a way to expunge the unwanted EFI update and eventually make it start working again.
An owner of a 2011 MacBook Air who hails from Greece was worried since there is no Apple store in his country. He tried to "revive" his machine by performing an SMC reset but it was futile. The warranty does not cover the issue and even the retailer had refused to extend some help. The local "official" Apple support had promised to fix it but with a certain fee.
Apple recommends that all MacBook Air computers should install the MacBook Air Software Update. There is even a guideline for users on how to use it. The EFI update has been designed to update the EFI firmware. First, users must make sure that their laptop's power cord is connected and plugged in a good power source. When the laptop restarts, the user will see a gray screen and a status bar that displays the update's progress. The update will take several minutes to complete. While the update is progressing, the user must avoid any interruption or shutting off power.
While the thread in Apple's Support page has seen an increase in user views and replies, it is still difficult to give the exact number of affected MacBook Air users. It is therefore advised that users who are thinking about installing the update should postpone it at a later date.