This has never happened to me before. My microSD card can't be read by my PC (using my card reader, it saysdrive not format when I borrowed another one), but oddly enough my R4 can read it! It wasn't a problem til I needed to update what's in it... Can I ask if it's safe to reformat it? I mean... my R4 may not read it after I do it... anyone?
If you format it, all data on the card will be lost. Hopefully you have a backup of your save files. Since you said you tried another reader, this usually happens when the MicroSD has corrupted data and/or is nearing the end of it's life. If you try to format it, it may come up saying it cannot because you don't have write access to the disc. That's another sign of it dying.
It's prolly the former... cause I had an accident when taking it off once (we had a brownout).... could that cause it? Well at any rate I'll try formatting it and hopefully it's not the end of it's life.
