My microSD card has randomly changed to read only and won’t let me format or copy data onto it.
Is there anything that I can do to format the card?
I run a Macintosh OS 10.9.
Resetting the PRAM may fix this issue. So first shut down the computer, then locate the keys i.e. command+option+P+R on the keyboard and turn on the Mac. Just then press and hold the above keys immediately, till the computer restarts. Remember to hold the keys before the grey screen appears and release the keys.