Problems installing DPP4 update on my iMac

[philipbaker]

I've just realised that my DPP4 is out of date, being version 4.12.60.0, so I've downloaded the latest one 4.16.10. but I can't get it to install. I've opened the zip file to show the installer and extracted the update but nothing happens. I've carried out the procedure with DPP closed down and open but it still shows the previous version in the 'About' menu. Switching the Mac off and restarting makes no difference either.
My iMac is running 10.14.6 Mojave.
Can anyone advise please?

[philipbaker]

This matter has now been resolved but it's too complicated to explain.

[Trev B]

I always think, to hell how I got there, I’m there