I've been using this guide to update my Rasbian version:
http://baddotrobot.com/blog/2017/10/26/upgrade-raspian-jessie-to-stretch/
However, after changing the files to use "Stretch" rather than "Jessie", on trying to use sudo apt-get update, I get this error:
W: Failed to fetch http://archive.raspberrypi.org/debian/dists/stretch/InRelease Unable to find expected entry 'staging/binary-armhf/Packages' in Release file (Wrong sources.list entry or malformed file)
How do I go about fixing this?