"Preparing SanDisk SD card, checking for errors." Cannot access SD card on phone.

[ThorHammerSmash]

Hi, I cannot access the content stored on my SD card (SD card 1) or add new files to it when it is in my Moto G (3rd gen) phone. What is strange is that I can access the content when the SD card is connected to my laptop, which suggests the SD card is fine...but then I tried another SD card (SD card 2) in my phone and the phone had no problem accessing it. You see my confusion? The problem seems to be a compatibility issue between the phone and SD card 1.

Any guidance would be gratefully received, as I am a complete novice in such matters!

Update: my phone says the SD card 1 is 'corrupted'.

 

[svim]

It sounds like that first microSD card might not be formatted incorrectly to be compatible with your phone. Cards can formatted with different file systems, your phone expects the card to be FAT32 or exFAT. Depending on what kind of laptop you have, it could be formatted as NTFS or HFS+. Be sure to copy everything off the card to your computer, then reformat it in your Moto G and see if that makes any difference. If it works out, don't forget to unmount it, put it back in you laptop and copy your files back.