MacOS – Can’t format SD Card after OS X Lion update to 10.7.4

bugformattingmacossd card

Today I tried to format my SD cards with no success. The only thing different that I did was updating to 10.7.4 this weekend. What can I do to re-enable this function?

The can't format part means I can't format to any filesystem. It shows "read only". The erase format is not enabled.

Another user here has confirmed the same problem. The SD cards in question format fine in a camera but I can't write to it when I plug it into MacBook Pro. This started to happen only after update to 10.7.4. The problems seems to stem from (or correlate with) Disk Utility greying out all options apart from 'verify disk'.

Inserting SD card to SD -> USB dongle works just fine, so it's only SD card slot which seems to have assigned 'read only' status.

It's weird it started to work fine for a while and again I can't write to or format the SD cards.

I've formated a SD card with both exFAT and FAT32 and tried to use it on my laptop with Linux and guess what happened? It was read only even in another computer, but I've formated it again using Linux utility and everything is fine.
But the SD saga continues on OS X Lion, as well as Mountain Lion and Mavericks.

It is annoying buying an Apple product and have this kind of headache, and the worst is that I don't have the possibility of walking in an Apple Store and ask a genius to solve it for me.

Best Answer

There are two likely possible causes for this:

  1. It's a hardware fault that just showed up, or
  2. It's a bug in OS X 10.7.4.

The best fix for both of these (currently) is to visit your local Apple Store's Genius Bar. In case 1, they'll fix your SD reader. In case 2, they'll pass the bug in OS X up the food chain so it can get fixed in 10.7.5 (they'll probably try to fix the hardware, too, just in case).