I just had to help a friend that could not open an SD card. Turns out its a normal problem and you just need to have two small packages installed. https://askubuntu.com/questions/451364/how-to-enable-exfat-in-ubuntu-14-04 Please include these two packages by default: exfat-fuse exfat-utils
This is a potential licensing issue due to Microsoft. With Microsoft joining the OIN, there is discussion now within Kubuntu/Ubuntu to get this passed through Canonical legal and have it included. Closing as upstream bug.