Не удается разблокировать Lockscreen (sddm)

rcpao@bun:~$ df
Filesystem                   1K-blocks       Used  Available Use% Mounted on
/dev/mapper/ubuntu--vg-root 1916153032  658404668 1160390336  37% /
none                                 4          0          4   0% /sys/fs/cgroup
udev                          16438692          4   16438688   1% /dev
tmpfs                          3289976       2156    3287820   1% /run
none                              5120          0       5120   0% /run/lock
none                          16449860      18768   16431092   1% /run/shm
none                            102400         48     102352   1% /run/user
/dev/sda1                       240972      98990     129541  44% /boot
/dev/sdc1                     60915712      20992   60894720   1% /media/rcpao/SD024-64GB

rcpao@bun:~$ sudo umount /dev/sdc1
[sudo] password for rcpao: 
rcpao@bun:~$

rcpao@bun:~$ sudo umount /media/rcpao/SD024-64GB
[sudo] password for rcpao: 
rcpao@bun:~$