why wont my galaxy s4 read my sd card?

[Jade Silva]

i have 2 SD cards and have been trying both but it will not read either one. before this happened my phone would randomly have pop ups on the scroll down bar saying "SD card removed unexpectedly" when i had never touched it to begin with.

 

[Pwnography-XXII]

What's the brand of it? I wish it's not SanDisk.