Fix crash

app/src/main/java/com/fongmi/android/tv/model/LiveViewModel.java

@@ -139,6 +139,7 @@ public class LiveViewModel extends ViewModel {
         Future<?> oldFuture = futures.get(type);
         if (oldFuture != null && !oldFuture.isDone()) oldFuture.cancel(true);
         Future<T> newFuture = App.submit(callable);
+        if (executor.isShutdown()) return;
         futures.put(type, newFuture);
         executor.execute(() -> {
             try {

app/src/main/java/com/fongmi/android/tv/model/SiteViewModel.java

@@ -256,6 +256,7 @@ public class SiteViewModel extends ViewModel {
 
     private void execute(MutableLiveData<Result> result, Callable<Result> callable) {
         if (future != null && !future.isDone()) future.cancel(true);
+        if (executor.isShutdown()) return;
         future = App.submit(callable);
         executor.execute(() -> {
             try {