It's possible to have multiple installations of X-Plane on your machine. However, it's necessary to make sure that the simulator installs file points to the desired installation.
On a machine with multiple installations of X-Plane 11, you need to configure which version is opened when launching X-Plane 11. To do this:
- Edit the C:\Users\[YOUR USER PROFILE]\AppData\Local\x-plane_install_11.txt file to reflect the location of the XP11 installation intended for use.
- Delete the scenery_packs.ini file from ...\X-Plane 11\Custom Scenery\ and allow XP11 to generate a new one when it is launched which will detect any new addons installed.