diff --git a/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSession.java b/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSession.java
index 25546acb95..514d9da073 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSession.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSession.java
@@ -209,23 +209,16 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
 
   @SuppressWarnings("deprecation")
   public void onMediaDrmEvent(int what) {
-    if (!isOpen()) {
-      return;
-    }
     switch (what) {
+      case ExoMediaDrm.EVENT_PROVISION_REQUIRED:
+        onProvisionRequired();
+        break;
       case ExoMediaDrm.EVENT_KEY_REQUIRED:
-        doLicense(false);
+        onKeysRequired();
         break;
       case ExoMediaDrm.EVENT_KEY_EXPIRED:
-        // When an already expired key is loaded MediaDrm sends this event immediately. Ignore
-        // this event if the state isn't STATE_OPENED_WITH_KEYS yet which means we're still
-        // waiting for key response.
         onKeysExpired();
         break;
-      case ExoMediaDrm.EVENT_PROVISION_REQUIRED:
-        state = STATE_OPENED;
-        provisioningManager.provisionRequired(this);
-        break;
       default:
         break;
     }
@@ -441,8 +434,21 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     }
   }
 
+  private void onProvisionRequired() {
+    if (mode == DefaultDrmSessionManager.MODE_PLAYBACK && isOpen()) {
+      state = STATE_OPENED;
+      provisioningManager.provisionRequired(this);
+    }
+  }
+
+  private void onKeysRequired() {
+    if (mode == DefaultDrmSessionManager.MODE_PLAYBACK && isOpen()) {
+      doLicense(/* allowRetry= */ false);
+    }
+  }
+
   private void onKeysExpired() {
-    if (state == STATE_OPENED_WITH_KEYS) {
+    if (mode == DefaultDrmSessionManager.MODE_PLAYBACK && state == STATE_OPENED_WITH_KEYS) {
       state = STATE_OPENED;
       onError(new KeysExpiredException());
     }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java b/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java
index d71c6fc64c..5f166c6114 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java
@@ -589,6 +589,10 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
 
   @Override
   public void provisionRequired(DefaultDrmSession<T> session) {
+    if (provisioningSessions.contains(session)) {
+      // The session has already requested provisioning.
+      return;
+    }
     provisioningSessions.add(session);
     if (provisioningSessions.size() == 1) {
       // This is the first session requesting provisioning, so have it perform the operation.
@@ -649,6 +653,10 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
     @Override
     public void handleMessage(Message msg) {
       byte[] sessionId = (byte[]) msg.obj;
+      if (sessionId == null) {
+        // The event is not associated with any particular session.
+        return;
+      }
       for (DefaultDrmSession<T> session : sessions) {
         if (session.hasSessionId(sessionId)) {
           session.onMediaDrmEvent(msg.what);
@@ -668,9 +676,7 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
         int event,
         int extra,
         @Nullable byte[] data) {
-      if (mode == DefaultDrmSessionManager.MODE_PLAYBACK) {
-        Assertions.checkNotNull(mediaDrmHandler).obtainMessage(event, sessionId).sendToTarget();
-      }
+      Assertions.checkNotNull(mediaDrmHandler).obtainMessage(event, sessionId).sendToTarget();
     }
 
   }