playlist checks

src/dash-playlist-loader.js

@@ -928,25 +928,29 @@
     }
   }
 
   excludeNonUsablePlaylists() {
     this.mainPlaylistLoader_.main.playlists.forEach((playlist) => {
+      if (!playlist.contentProtection.mp4protection ||
+        !playlist.contentProtection.mp4protection.attributes['cenc:default_KID']) {
+        return;
+      }
       const playlistKID = playlist.contentProtection.mp4protection.attributes['cenc:default_KID'].replace('-', '');
       const hasUsableKeystatus = this.keyStatusMap.has(playlistKID) && this.keyStatusMap.get(playlistKID) === 'usable';
 
       if (!hasUsableKeystatus) {
         playlist.excludeUntil = Infinity;
         playlist.lastExcludeReason_ = 'non-usable';
       } else {
         delete playlist.excludeUntil;
         delete playlist.lastExcludeReason_;
       }
     });
   }
 
   addKeyStatus(keyId, status) {
     // 32 digit keyId hex string.
     const keyIdHexString = arrayBufferToHexString(keyId).slice(0, 32);
 
     this.keyStatusMap_.set(keyIdHexString, status);
   }
 }