Looks like an acer-wmi issue. Could you try what in the below link and let me know the result please?
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/836865/comments/13
Looks like an acer-wmi issue. Could you try what in the below link and let me know the result please?
https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/836865/ comments/ 13