Thank you for your quick response and assistance - you have partially solved the problem for me. When I put the add-on folder in the …8wekyb3d8bbwe/LocalCache/Packages/Community folder then the addon loads OK in flightsim and all is good. This however does not answer the question of why, when the addon is placed in the Community folder (that is located with the Official folder) it will not load in the sim!!
The last entry in the UserCfg.opt file is:
InstalledPackagesPath “C:\Users\Neil F Wright\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\Packages”
Does this line need to have \Community added?