OK, curiosity got the better of me, and so I am in the shack, and I ran the installer for JTAlert 2.50.0 and it actually ran without any issues, and I got the following message on completion.
That makes me think that the issue is with SDR#, but it did make me hold off even trying it.
When you suggested trying it anyway, I thought why not, and I don't think I am surprised that it ran, given your previous message.
I am not sure why SDR# won't run though, but I will find another way,
Thanks for all your support Laurie,
73 de Phil GU0SUP