Why do I get the message SDcard share the same disk with os when I try to put data on the SD card?

[josmith1971]

SDcard share the same disk with os

My son has a samsung galaxy fame. The memory is tiny so I bought him an sd card. I'm trying to move apps across. I installed apps to sd but when I try and carry out a transfer I just get the above message. Can anyone help please?

Thank you