I can enter into my SD CARD, but i cant transfer app data to the SD CARD

i mean like, i can play music from the SD Card, i can watch videos, my phone detects the sd card in the options but i cant transfer the app data to the sd card, it says that i dont have enough space left, and i have like 3gb of space left in the sd card

I have the Cyanogenmod 12.1 with the 5.1.1 Lollipop Software