Hi Myron, thank you for helping.
I am not at Hogfather yet, attempted and failed a few times. I have people writing at the moment so need to choose my time when I can diagnose what is failing with that.
I have dwedit installed thanks so it's fine for me but not all the authors can cope with markdown.
Have deleted the cache and restarted... didn't work: https://www.screencast.com/t/BC8kSD0y
I have kicked everyone off and will attempt an update to Hogfather.
As a general rule do you think one should clear out this cache directory form time to time?