You need to use a Theme.AppCompat theme

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dji.sdk.sample/com.dji.sdk.sample.common.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2454)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2516)
at android.app.ActivityThread.access$1200(ActivityThread.java:163)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1374)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5601)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:964)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:759)
Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
at android.support.v7.app.AppCompatDelegateImplV7.createSubDecor(AppCompatDelegateImplV7.java:331)
at android.support.v7.app.AppCompatDelegateImplV7.ensureSubDecor(AppCompatDelegateImplV7.java:300)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:264)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:130)
at com.dji.sdk.sample.common.MainActivity.onCreate(MainActivity.java:81)
at android.app.Activity.performCreate(Activity.java:6100)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1109)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2407)
... 10 more
java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
at android.support.v7.app.AppCompatDelegateImplV7.createSubDecor(AppCompatDelegateImplV7.java:331)
at android.support.v7.app.AppCompatDelegateImplV7.ensureSubDecor(AppCompatDelegateImplV7.java:300)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:264)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:130)
at com.dji.sdk.sample.common.MainActivity.onCreate(MainActivity.java:81)
at android.app.Activity.performCreate(Activity.java:6100)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1109)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2407)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2516)
at android.app.ActivityThread.access$1200(ActivityThread.java:163)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1374)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5601)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:964)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:759)