Recently got myself a 16gb micro SD Card to replace the 8GB one on my phone. Plugged it into the Macbook Pro using the adapter. Couldn’t write to it but could read it. Same thing happened for the 8GB one that worked perfectly on the phone too. And it couldn’t write in both locked/unlocked mode.
Turns out you actually have to push the write protect switch to the center of the switch, such that it tends slightly towards the unlocked position, but not all the way. Your switch has to be floating between the 2 extreme ends.
Who the heck does that? Way to go for usability Apple. And there I was thinking that you make hardware and software that works well together. Guess I was wrong.
And no, I’m not the only one with this problem. [Link]