Android studio design editor is unavailable until after a successful project sync

Android Studio Error. design editor is unavailable until after a successful project sync. this problem can be solve in two ways. 1 sync project with gradle file. 2 checked your installed sdk version if the install sdk version can not match with the compile sdk version and target sdk version and also with the build tool. watch video and slow your problem with in 1 mint the problem is not defacult if you look at careful with the option 2 sdk version. android stodio. android app development.