Thanks Nigel,
I managed to blindly stumble through things what were alien to me and with your advice, I now have JRE11 and DP 5.2.
One more question. I did look for a list of decoder definitions that I could download and use, but couldn't work out where to go for them. I did find your list of MS decoders that you've written, but couldn't find how to download them if I need to. Luckily the update to DP 5.2 has put them on there, but I might need to use more as and when they come out.