Nightly builds are unstable and may not work at all. They are not meant for daily flying use and should only be used for testing.
We provide these so (aircraft) developers can explore the latest development status. Due to the transition to a new rendering pipeline, many aircraft and scenery will currently render incorrectly. Additionally, the user interface is being redesigned, which may result in broken dialogs and/or menus.
Download a stable release if you are looking for a reliable flying experience.