Let's try assigning a size to /dev/shm.
Modify your /etc/fstab addig size to /dev/shm:
tmpfs /dev/shm tmpfs defaults,size=2g 0 0
(I used 2Gbyte, but you can put any size you want).
And then remount it with sudo mount -o remount /dev/shm
is there enough space on your device?
(let's see it with df -h