Phone says SD card is inserted, so why can't I use it anymore?

[AC Question]

Hi! I got myself an LG android phone a few months ago before moving, cuz I needed a new one.
The SD card I bought for it worked totally fine, I stored a bunch of music on it, and then one day..it just stopped working. I've re-inserted it, cleaned it, done everything possible with it and it just doesn't work. When I insert it, my phone says "SD Card Inserted", but when I try to mount the SD card through settings, the settings section crashes. I have no space left on my phone and I'm having to delete photos to take more photos :/ this is seriously un-cool, so some help would be greatly appreciated.

 

[Rukbat]

Are you having trouble reading it or writing to it?

If the phone can't read it, and a PC can, bring the phone back and have it repaired or replaced. If the phone can't write to it, and you're running 4.4 or later, only the app that created a folder on the SD card can write to it. The SD card is not part of the file system, it's not connected storage (which it was up to 4.3). Save all your music to a PC, using a card reader, delete the folder, use your music app to create a folder, then copy the files back to the folder using the card reader. (Windows can't see Linux's permissions, so it writes wherever you tell it to.)