Troubleshooting tip – may or may not help:
Sometimes, a 3rd-party add-on aircraft just does not seem to work properly or initialize correctly.
A workaround is first to load up the Default Cessna 172, then, once it is loaded, from the pull-down menu, click Flight –> Flight Configuration and change your aircraft to your 3rd-party aircraft.
Reason this sometimes works:
Sometimes X-Plane needs to be initialized with a default aircraft first. This is an old tip, but it sometimes applies even with X-Plane 12 – compatible add-on aircraft or mods.