diff --git a/services/core/java/com/android/server/wm/ActivityStarter.java b/services/core/java/com/android/server/wm/ActivityStarter.java
index 1b0bec5f34026..df046634da48e 100644
--- a/services/core/java/com/android/server/wm/ActivityStarter.java
+++ b/services/core/java/com/android/server/wm/ActivityStarter.java
@@ -279,6 +279,9 @@ class ActivityStarter {
             ActivityStarter starter = mStarterPool.acquire();
 
             if (starter == null) {
+                if (mService.mRootWindowContainer == null) {
+                    throw new IllegalStateException("Too early to start activity.");
+                }
                 starter = new ActivityStarter(mController, mService, mSupervisor, mInterceptor);
             }
 
diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index ce709783c3bd0..cc398ee24f053 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -183,6 +183,7 @@ import android.os.IUserManager;
 import android.os.LocaleList;
 import android.os.Looper;
 import android.os.Message;
+import android.os.Parcel;
 import android.os.PowerManager;
 import android.os.PowerManagerInternal;
 import android.os.Process;
@@ -4938,6 +4939,21 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
         return allUids.contains(uid);
     }
 
+    @Override
+    public boolean onTransact(int code, Parcel data, Parcel reply, int flags)
+            throws RemoteException {
+        try {
+            return super.onTransact(code, data, reply, flags);
+        } catch (RuntimeException e) {
+            if (!(e instanceof SecurityException)) {
+                Slog.w(TAG, "Activity Task Manager onTransact aborts "
+                        + " UID:" + Binder.getCallingUid()
+                        + " PID:" + Binder.getCallingPid(), e);
+            }
+            throw e;
+        }
+    }
+
     final class H extends Handler {
         static final int REPORT_TIME_TRACKER_MSG = 1;