When I installed MSFS 2024 on the 29th, my MSFS 2020 (uninstalled itself without notice) reinstalled to the same, previous location and all content was gone. Fortunately, I keep all my addons on a separate drive, linked to the respective community folder so nothing was actually lost. However, in trying to reinstate things, I found I had four empty community folders. Trial and error later I managed to identify the operative folder for each version. MSFS installation file/folder hierachy remains very messy:
