Hi Mach1,
Just like you I am a standard flight simmer. I have no connection with Laminar Research.
If you trawl back through the recent Q&A pages others have asked the same question. I understand that from my readings, once you upgrade to the next version ie from 10.45 to 10.50, there is no ability to backtrack unless you backed up 10.45 "totally" with a rename whereby you need to delete the newer version and recover the older 10-.45. In short words, can't be done.
Glenn