OK. Thanks for all the suggestions guys.
All fixed and running again..... at last.
Rather than spend fruitless hours trying to find out what the Win10 update might have done/changed, I opted to drag across my working copy from my external back-up drive and copy in the current TRACKS/SETUPS/SEASONS folders to update.
Renamed the current suspect SIERRA install as oldSIERRA and allowed the backup copy to take the SIERRA name. This also allowed the current GEM install to work with the replacement SIERRA install.
That all worked fine and GEM fired up the 67 cars at Albi. (So it would appear that "something" changed with GPL and not with GEM during the Windows update?)
I then hit a snag of my own ineptitude because although I had steering and pedals, I had no gears
Which was very odd as all had worked fine yesterday. Recalibrated the Bodnar gears and tried multiple times to persuade GPL to allow me some gearshifts.
Eventually traced the problem to GPLShift. I had it installed and working in the current suspect oldSIERRA, but although the BACKUP copy had GPLShift files within it, they had never actually been activated by the GPLShift_patch.exe, because I only switched to H pattern after I had saved that working copy.
Once I did that everything worked 100%, even Pribluda.
But I am still not any faster
@ Axel. When everything went t*ts up with GPL and I could not get it to work through GEM, it was a last desperate act to try and launch GPL from the Sierra folder, just to see if I could bi-pass GEM and check if GPL still worked. I am aware that once GEM is operational it should be allowed to function uninterrupted, but it wasn't so I figured that I had nothing to lose.
If I had enough RAM between my ears and coupled to a modern thought processor, I would switch to Linux in an instant and tell Mr Gates to go insert a window where the sun don't shine!! But, I suspect that I could find myself in a very deep software swamp if I went down that route
