Since the update I have repeated error message related to BTRFS. This started to happen with the update, I checked in /var/log/messages
2018-12-10 18:55:24 err netdata[8046]: BTRFS: failed to read '/sys/fs/btrfs/0df3df80-9c53-438e-9905-07e5de714a81/allocation/data/total_bytes'
2018-12-10 18:56:01 info /usr/sbin/cron[13656]: (root) CMD (/usr/bin/rainbow_button_sync.sh)
2018-12-10 18:56:01 info /usr/sbin/cron[13657]: (root) CMD (nethist_stats.lua)
2018-12-10 18:56:24 err netdata[8046]: BTRFS: failed to read '/sys/fs/btrfs/0df3df80-9c53-438e-9905-07e5de714a81/allocation/data/total_bytes'
2018-12-10 18:57:01 info /usr/sbin/cron[13715]: (root) CMD (/usr/bin/rainbow_button_sync.sh)
2018-12-10 18:57:26 err netdata[8046]: BTRFS: failed to read '/sys/fs/btrfs/0df3df80-9c53-438e-9905-07e5de714a81/allocation/data/total_bytes'
2018-12-10 18:58:01 info /usr/sbin/cron[13750]: (root) CMD (nethist_stats.lua)
2018-12-10 18:58:01 info /usr/sbin/cron[13751]: (root) CMD (/usr/bin/rainbow_button_sync.sh)
2018-12-10 18:58:26 err netdata[8046]: BTRFS: failed to read '/sys/fs/btrfs/0df3df80-9c53-438e-9905-07e5de714a81/allocation/data/total_bytes'