Problem was solved by complete uninstall (including ALL files/folders left behind after using 'Unistall'). This would suggest to me that it has nothing to do with any anti-virus program.
It was surely your antivirus, no questions about it.
(I live dangerously and switch my anti-virus OFF when using my flight sim)
Then you cannot be sure you don't have a real virus instead. Also, I personally witnessed several antivirus products that STILL continued to block files, even if the LOOKED "switched off", because their Windows service was still running, even if the antivirus seemed to be turned off.
That's why we never suggested to turn it off, but to add the whole "Addon Manager" folder to the Exclusion list.
However, both programs, GSX and the Expansion Pack, now start in 'Trial Mode' and require re-registering every time I restart my computer OR restart P3Dv4.5. This is a nuisance,but it at least they recognise my valid key code. Is there a way I can avoid having to re-register each time like this?
That's not normal either, and it can either caused by the antivirus, or but can also caused by a problem with your user account. Try all the following:
- add the whole "Addon Manager" folder to the Exclusion list.
- run the FSDT LIve Update again
- RESTART WINDOWS
- DEACTIVATE from the Addon Manager, and Reactivate