Unable to update

hi all, If I try to update via GUI I get the below, any ideas ?

LAST ENTRIES ON THE LOG FILE
Starting update via service-runner-update.sh (v2.0) >
Filesystem is unlocked - Write access
type ' rpi-ro ' to lock
- emonSD version: emonSD-26Oct17
ERROR: emonSD base image old or undefined...update will not continue
See latest verson: https://github.com/openenergymonitor/emonpi/wiki/emonSD-pre-built-SD-card-Download-&-Change-Log
Stopping update

As per pinned messsage.