Thanks @watou, I think my issue is related to this post.
Items file:
String Heating_DaikinMode “Daikin Mode [%S]” { daikin=“living:mode” }
I just copied the wiki code format and used a mappings string in the sitemap file:
Selection item=Heating_DaikinMode mappings=[Auto=“Auto”, Cool=“Cool”, Dry=“Dry”, Heat=“Heat”, OnlyFan=“Fan”]
I might give the older 1.7 jar a go and see if that plays nicely in OH2, but I use a Daikin Skyfi unit, which I thought (wrongly?) was only supported with the jDaikin integration?