diff --git a/src/com/android/customization/model/theme/ThemeBundle.java b/src/com/android/customization/model/theme/ThemeBundle.java
index 8cb2865..43b07ff 100644
--- a/src/com/android/customization/model/theme/ThemeBundle.java
+++ b/src/com/android/customization/model/theme/ThemeBundle.java
@@ -62,6 +62,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
  * Represents a Theme component available in the system as a "persona" bundle.
@@ -87,7 +88,7 @@
         mTitle = title;
         mIsDefault = isDefault;
         mPreviewInfo = previewInfo;
-        mPackagesByCategory = Collections.unmodifiableMap(overlayPackages);
+        mPackagesByCategory = Collections.unmodifiableMap(removeNullValues(overlayPackages));
     }
 
     @Override
@@ -214,6 +215,13 @@
         }
     }
 
+    private Map<String, String> removeNullValues(Map<String, String> map) {
+        return map.entrySet()
+                .stream()
+                .filter(entry -> entry.getValue() != null)
+                .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+    }
+
     protected CharSequence getContentDescription(Context context) {
         if (mContentDescription == null) {
             CharSequence defaultName = context.getString(R.string.default_theme_title);
diff --git a/src/com/android/customization/picker/WallpaperPreviewer.java b/src/com/android/customization/picker/WallpaperPreviewer.java
index 0185925..8f69d59 100644
--- a/src/com/android/customization/picker/WallpaperPreviewer.java
+++ b/src/com/android/customization/picker/WallpaperPreviewer.java
@@ -174,7 +174,7 @@
 
         mWallpaperConnection.setVisibility(true);
         mHomePreview.post(() -> {
-            if (!mWallpaperConnection.connect()) {
+            if (mWallpaperConnection != null && !mWallpaperConnection.connect()) {
                 mWallpaperConnection = null;
                 LiveTileOverlay.INSTANCE.detach(mHomePreview.getOverlay());
             }