material-components/material-components-android · error · UnsupportedOperationException

%s does not support submenus

Error message

%s does not support submenus

What it means

NavigationBarMenu.addSubMenu throws UnsupportedOperationException when the navigation bar was constructed without submenu support (subMenuSupported=false). BottomNavigationView and NavigationBarView historically disallow submenus because their item layout has no way to render nested menus; only specific configurations (e.g. NavigationBarView with expanded selections) enable it.

Source

Thrown at lib/java/com/google/android/material/navigation/NavigationBarMenu.java:68

      @NonNull Class<?> viewClass,
      int maxItemCount,
      boolean subMenuSupported) {
    super(context);
    this.viewClass = viewClass;
    this.maxItemCount = maxItemCount;
    this.subMenuSupported = subMenuSupported;
  }

  /** Returns the maximum number of items that can be shown in NavigationBarMenu. */
  public int getMaxItemCount() {
    return maxItemCount;
  }

  @NonNull
  @Override
  public SubMenu addSubMenu(int group, int id, int categoryOrder, @NonNull CharSequence title) {
    if (!subMenuSupported) {
      throw new UnsupportedOperationException(
          viewClass.getSimpleName() + " does not support submenus");
    }
    final MenuItemImpl item = (MenuItemImpl) addInternal(group, id, categoryOrder, title);
    final SubMenuBuilder subMenu = new NavigationBarSubMenu(getContext(), this, item);
    item.setSubMenu(subMenu);
    return subMenu;
  }

  @Override
  @NonNull
  protected MenuItem addInternal(
      int group, int id, int categoryOrder, @NonNull CharSequence title) {
    if (size() + 1 > maxItemCount) {
      String viewClassName = viewClass.getSimpleName();
      throw new IllegalArgumentException(
          "Maximum number of items supported by "
              + viewClassName
              + " is "

View on GitHub (pinned to ac7e18efee)

Solutions

1. Remove nested <menu> elements from the menu XML used with BottomNavigationView/NavigationBarView
2. Use a separate simplified menu resource for bottom navigation with only top-level <item> entries
3. If drill-down navigation is needed, navigate to a new screen/fragment instead of using a submenu

Example fix

<!-- before: menu_bottom.xml used by BottomNavigationView -->
<item android:id="@+id/nav_more" android:title="More">
  <menu>
    <item android:id="@+id/nav_settings" android:title="Settings"/>
  </menu>
</item>
<!-- after -->
<item android:id="@+id/nav_settings" android:title="Settings"/>

// Strip submenu declarations before inflating into a view that rejects them
fun canHaveSubmenus(view: NavigationBarView): Boolean =
    view.menu is NavigationBarMenu && (view.menu as NavigationBarMenu).let { /* consult API level docs */ true } // simplest: don't nest menus in bottom nav at all

catch (e: UnsupportedOperationException) { Log.w(TAG, "View does not support submenus; using flat menu", e); inflateFlatMenu() }

When it happens

Trigger: Inflating a menu XML that contains a <menu> nested inside an <item> and applying it to a BottomNavigationView/NavigationBarView constructed with subMenuSupported=false; or calling getMenu().addSubMenu(...) programmatically on such a view.

Common situations: Sharing one menu XML between NavigationView (drawer, submenus OK) and BottomNavigationView (submenus rejected); copy-pasting drawer menu layouts into bottom navigation.

Related errors

• Maximum number of items supported by %s is %d. Limit can be
• Only one layer of submenu is supported; a submenu inside a s
• %d is not a valid view id
• Called setCheckedItem(MenuItem) with an item that is not in
• secondaryIconGravity cannot have the same alignment as iconG

AI-assisted analysis of material-components/material-components-android@ac7e18efee (2026-08-14). Data as JSON: /api/errors/66059850e2834043. Report an issue: GitHub.