Why has my Boost ZTE Sequent N9515 stopped recognizing my toshiba 16GB sd card?

A

AC Question

I've never been able to store my apps onto my sd card. I have manually went in and moved files to my sd card but ended up losing my pictures and important notes because i didn't know that those were the files that i tampered with and erased them. Now my phone memory is full and i cant update any of my apps or store anything else to my phone. So im guessing that my sd card is not being recognized. Does it need to be formatted? Please help.