diff --git a/source/packages/com_mokosuitebackup/src/Extension/MokoSuiteBackupComponent.php b/source/packages/com_mokosuitebackup/src/Extension/MokoSuiteBackupComponent.php
index e6fad77..6332938 100644
--- a/source/packages/com_mokosuitebackup/src/Extension/MokoSuiteBackupComponent.php
+++ b/source/packages/com_mokosuitebackup/src/Extension/MokoSuiteBackupComponent.php
@@ -12,6 +12,7 @@ namespace Joomla\Component\MokoSuiteBackup\Administrator\Extension;
 
 defined('_JEXEC') or die;
 
+use Joomla\CMS\Document\HtmlDocument;
 use Joomla\CMS\Extension\MVCComponent;
 use Joomla\CMS\Factory;
 
@@ -28,7 +29,13 @@ class MokoSuiteBackupComponent extends MVCComponent
 				return;
 			}
 
-			$wa = $app->getDocument()->getWebAssetManager();
+			$doc = $app->getDocument();
+
+			if (!($doc instanceof HtmlDocument)) {
+				return;
+			}
+
+			$wa = $doc->getWebAssetManager();
 			$wa->addInlineStyle(
 				'.main-nav a[href*="com_mokosuitebackup"][href*="view=dashboard"] .sidebar-item-title::before,'
 				. ' .main-nav a[href*="com_mokosuitebackup"][href*="view=backups"] .sidebar-item-title::before,'
@@ -38,7 +45,7 @@ class MokoSuiteBackupComponent extends MVCComponent
 				. ' .main-nav a[href*="com_mokosuitebackup"][href*="view=backups"] .sidebar-item-title::before { content: "\f1c0"; }'
 				. ' .main-nav a[href*="com_mokosuitebackup"][href*="view=profiles"] .sidebar-item-title::before { content: "\f013"; }'
 			);
-		} catch (\Throwable $e) {
+		} catch (\RuntimeException $e) {
 			error_log('MokoSuiteBackup: boot() CSS injection failed: ' . $e->getMessage());
 		}
 	}
diff --git a/source/script.php b/source/script.php
index 689e702..f472862 100644
--- a/source/script.php
+++ b/source/script.php
@@ -40,6 +40,15 @@ class Pkg_MokoSuiteBackupInstallerScript
 	 */
 	public function preflight(string $type, InstallerAdapter $parent): bool
 	{
+		if (version_compare(JVERSION, $this->minimumJoomla, '<')) {
+			Factory::getApplication()->enqueueMessage(
+				Text::sprintf('PKG_MOKOJOOMBACKUP_JOOMLA_VERSION_ERROR', $this->minimumJoomla),
+				'error'
+			);
+
+			return false;
+		}
+
 		if (version_compare(PHP_VERSION, $this->minimumPhp, '<')) {
 			Factory::getApplication()->enqueueMessage(
 				Text::sprintf('PKG_MOKOJOOMBACKUP_PHP_VERSION_ERROR', $this->minimumPhp),
@@ -57,14 +66,6 @@ class Pkg_MokoSuiteBackupInstallerScript
 		return true;
 	}
 
-	/**
-	 * Called after install/update.
-	 *
-	 * @param   string            $type    Action type
-	 * @param   InstallerAdapter  $parent  Installer adapter
-	 *
-	 * @return  void
-	 */
 	/**
 	 * Called before install/update to preserve the download key.
 	 *
@@ -100,113 +101,43 @@ class Pkg_MokoSuiteBackupInstallerScript
 			if (!empty($key)) {
 				$this->savedDownloadKey = $key;
 			}
-		} catch (\Throwable $e) {
+		} catch (\Exception $e) {
 			error_log('MokoSuiteBackup: Could not save download key: ' . $e->getMessage());
 		}
 	}
 
+	/**
+	 * Called after install/update/uninstall.
+	 *
+	 * @param   string            $type    Action type (install, update, uninstall)
+	 * @param   InstallerAdapter  $parent  Installer adapter
+	 *
+	 * @return  void
+	 */
 	public function postflight(string $type, InstallerAdapter $parent): void
 	{
+		if ($type === 'uninstall') {
+			return;
+		}
+
 		// Restore download key if it was saved before update
 		if ($this->savedDownloadKey !== null) {
 			$this->restoreDownloadKey();
 		}
 
 		if ($type === 'install') {
-			// Enable the system plugin automatically on fresh install
-			$db    = Factory::getDbo();
-			$query = $db->getQuery(true)
-				->update($db->quoteName('#__extensions'))
-				->set($db->quoteName('enabled') . ' = 1')
-				->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
-				->where($db->quoteName('folder') . ' = ' . $db->quote('system'))
-				->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
-
-			$db->setQuery($query);
-			$db->execute();
-
-			// Enable the quickicon plugin automatically
-			$query = $db->getQuery(true)
-				->update($db->quoteName('#__extensions'))
-				->set($db->quoteName('enabled') . ' = 1')
-				->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
-				->where($db->quoteName('folder') . ' = ' . $db->quote('quickicon'))
-				->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
-
-			$db->setQuery($query);
-			$db->execute();
-
-			// Enable the task plugin automatically
-			$query = $db->getQuery(true)
-				->update($db->quoteName('#__extensions'))
-				->set($db->quoteName('enabled') . ' = 1')
-				->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
-				->where($db->quoteName('folder') . ' = ' . $db->quote('task'))
-				->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
-
-			$db->setQuery($query);
-			$db->execute();
-
-			// Enable the webservices plugin automatically
-			$query = $db->getQuery(true)
-				->update($db->quoteName('#__extensions'))
-				->set($db->quoteName('enabled') . ' = 1')
-				->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
-				->where($db->quoteName('folder') . ' = ' . $db->quote('webservices'))
-				->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
-
-			$db->setQuery($query);
-			$db->execute();
-
-			// Enable the console plugin automatically
-			$query = $db->getQuery(true)
-				->update($db->quoteName('#__extensions'))
-				->set($db->quoteName('enabled') . ' = 1')
-				->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
-				->where($db->quoteName('folder') . ' = ' . $db->quote('console'))
-				->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
-
-			$db->setQuery($query);
-			$db->execute();
-
-			// Enable the content plugin automatically
-			$query = $db->getQuery(true)
-				->update($db->quoteName('#__extensions'))
-				->set($db->quoteName('enabled') . ' = 1')
-				->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
-				->where($db->quoteName('folder') . ' = ' . $db->quote('content'))
-				->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
-
-			$db->setQuery($query);
-			$db->execute();
-
-			// Enable the actionlog plugin automatically
-			$query = $db->getQuery(true)
-				->update($db->quoteName('#__extensions'))
-				->set($db->quoteName('enabled') . ' = 1')
-				->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
-				->where($db->quoteName('folder') . ' = ' . $db->quote('actionlog'))
-				->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
-
-			$db->setQuery($query);
-			$db->execute();
+			// Enable all bundled plugins on fresh install
+			$this->enableBundledPlugins();
 
 			// Create default backup directory in site root
-			$backupDir = JPATH_ROOT . '/backups';
+			$this->createBackupDirectory();
 
-			if (!is_dir($backupDir)) {
-				@mkdir($backupDir, 0755, true);
-			}
-
-			// Create default scheduled task — every 30 days, profile 1
+			// Create default scheduled task for backup automation
 			$this->createDefaultScheduledTask();
 		}
 
-		if ($type === 'uninstall') {
-			return;
-		}
-
-		// Ensure submenu items exist (Joomla only creates them on fresh install)
+		// Ensure submenu items exist and are up to date
+		// (Joomla may not add new submenu entries or update params on upgrades)
 		$this->ensureSubmenuItems();
 
 		// Sync submenu icons in #__menu (Joomla doesn't update icons on upgrades)
@@ -215,8 +146,8 @@ class Pkg_MokoSuiteBackupInstallerScript
 		// Warn if no license key configured
 		$this->warnMissingLicenseKey();
 
-		// Warn if any profile still uses the default backup directory
-		$this->warnDefaultBackupDir();
+		// Migrate profiles with old default backup_dir values to [DEFAULT_DIR] placeholder
+		$this->migrateDefaultBackupDir();
 
 		// Remind user to review backup profile settings
 		if ($type === 'install') {
@@ -232,11 +163,70 @@ class Pkg_MokoSuiteBackupInstallerScript
 		}
 	}
 
-	private function warnDefaultBackupDir(): void
+	private function enableBundledPlugins(): void
+	{
+		$folders = ['system', 'quickicon', 'task', 'webservices', 'console', 'content', 'actionlog'];
+		$db      = Factory::getDbo();
+
+		foreach ($folders as $folder) {
+			try {
+				$query = $db->getQuery(true)
+					->update($db->quoteName('#__extensions'))
+					->set($db->quoteName('enabled') . ' = 1')
+					->where($db->quoteName('type') . ' = ' . $db->quote('plugin'))
+					->where($db->quoteName('folder') . ' = ' . $db->quote($folder))
+					->where($db->quoteName('element') . ' = ' . $db->quote('mokosuitebackup'));
+				$db->setQuery($query);
+				$db->execute();
+			} catch (\Exception $e) {
+				error_log('MokoSuiteBackup: Failed to enable ' . $folder . ' plugin: ' . $e->getMessage());
+				Factory::getApplication()->enqueueMessage(
+					'MokoSuiteBackup: Could not enable the ' . $folder . ' plugin. '
+					. 'Please enable it manually in Extensions &rarr; Plugins.',
+					'warning'
+				);
+			}
+		}
+	}
+
+	private function createBackupDirectory(): void
+	{
+		$backupDir = JPATH_ROOT . '/backups';
+
+		if (is_dir($backupDir)) {
+			return;
+		}
+
+		if (!mkdir($backupDir, 0755, true)) {
+			error_log('MokoSuiteBackup: Failed to create default backup directory: ' . $backupDir);
+			Factory::getApplication()->enqueueMessage(
+				'MokoSuiteBackup could not create the default backup directory at <code>'
+				. htmlspecialchars($backupDir) . '</code>. '
+				. 'Please create it manually and ensure the web server has write permissions.',
+				'warning'
+			);
+
+			return;
+		}
+
+		// Protect directory from direct web access
+		$htaccess = $backupDir . '/.htaccess';
+
+		if (!file_exists($htaccess)) {
+			file_put_contents($htaccess, "Order Deny,Allow\nDeny from all\n");
+		}
+
+		$indexHtml = $backupDir . '/index.html';
+
+		if (!file_exists($indexHtml)) {
+			file_put_contents($indexHtml, '<!DOCTYPE html><title></title>');
+		}
+	}
+
+	private function migrateDefaultBackupDir(): void
 	{
 		try {
 			$db    = Factory::getDbo();
-			// Check for profiles using old literal defaults — migrate to [DEFAULT_DIR]
 			$oldDefaults = [
 				'administrator/components/com_mokosuitebackup/backups',
 				'administrator/components/com_mokojoombackup/backups',
@@ -254,7 +244,6 @@ class Pkg_MokoSuiteBackupInstallerScript
 			$db->setQuery($query);
 
 			if ((int) $db->loadResult() > 0) {
-				// Auto-migrate old defaults to [DEFAULT_DIR] placeholder
 				$update = $db->getQuery(true)
 					->update($db->quoteName('#__mokosuitebackup_profiles'))
 					->set($db->quoteName('backup_dir') . ' = ' . $db->quote('[DEFAULT_DIR]'))
@@ -264,9 +253,15 @@ class Pkg_MokoSuiteBackupInstallerScript
 						. ' OR ' . $db->quoteName('backup_dir') . ' IS NULL)');
 				$db->setQuery($update);
 				$db->execute();
+
+				$migrated = $db->getAffectedRows();
+
+				if ($migrated > 0) {
+					error_log('MokoSuiteBackup: Migrated ' . $migrated . ' profile(s) from legacy backup_dir to [DEFAULT_DIR]');
+				}
 			}
-		} catch (\Throwable $e) {
-			error_log('MokoSuiteBackup: warnDefaultBackupDir() failed: ' . $e->getMessage());
+		} catch (\Exception $e) {
+			error_log('MokoSuiteBackup: migrateDefaultBackupDir() failed: ' . $e->getMessage());
 		}
 	}
 
@@ -320,12 +315,12 @@ class Pkg_MokoSuiteBackupInstallerScript
 				'cli_exclusive'   => 0,
 				'note'            => '',
 				'created'         => $now,
-				'created_by'      => Factory::getApplication()->getIdentity()->id ?? 0,
+				'created_by'      => Factory::getApplication()->getIdentity()?->id ?? 0,
 				'next_execution'  => date('Y-m-d 03:00:00', strtotime('+1 day')),
 			];
 
 			$db->insertObject('#__scheduler_tasks', $task);
-		} catch (\Throwable $e) {
+		} catch (\Exception $e) {
 			error_log('MokoSuiteBackup: createDefaultScheduledTask() failed: ' . $e->getMessage());
 		}
 	}
@@ -333,9 +328,9 @@ class Pkg_MokoSuiteBackupInstallerScript
 	/**
 	 * Ensure admin submenu items exist in #__menu.
 	 *
-	 * On updates Joomla does not re-create submenu entries from the manifest,
-	 * so we use the Installer's own _buildAdminMenus pathway via the
-	 * component's MenuTable API to create any missing items.
+	 * On updates Joomla may not add new submenu entries or update params,
+	 * so we manually create missing items using MenuTable for correct
+	 * nested set positioning (lft/rgt values).
 	 */
 	private function ensureSubmenuItems(): void
 	{
@@ -375,6 +370,7 @@ class Pkg_MokoSuiteBackupInstallerScript
 			$parent = $db->loadObject();
 
 			if (!$parent) {
+				error_log('MokoSuiteBackup: ensureSubmenuItems() — parent menu item not found');
 				return;
 			}
 
@@ -389,28 +385,31 @@ class Pkg_MokoSuiteBackupInstallerScript
 			$componentId = (int) $db->loadResult();
 
 			if (!$componentId) {
+				error_log('MokoSuiteBackup: ensureSubmenuItems() — component extension_id not found');
 				return;
 			}
 
 			foreach ($submenus as $submenu) {
-				$params = json_encode(['menu_icon' => $submenu['menu_icon']]);
-
 				// Check if this submenu item already exists
 				$query = $db->getQuery(true)
-					->select($db->quoteName('id'))
+					->select([$db->quoteName('id'), $db->quoteName('params')])
 					->from($db->quoteName('#__menu'))
 					->where($db->quoteName('client_id') . ' = 1')
 					->where($db->quoteName('link') . ' = ' . $db->quote($submenu['link']))
 					->setLimit(1);
 				$db->setQuery($query);
-				$existingId = (int) $db->loadResult();
+				$existing = $db->loadObject();
+
+				if ($existing) {
+					// Merge menu_icon into existing params to preserve other settings
+					$existingParams = json_decode($existing->params ?? '{}', true) ?: [];
+					$existingParams['menu_icon'] = $submenu['menu_icon'];
+					$mergedParams = json_encode($existingParams);
 
-				if ($existingId > 0) {
-					// Update params on existing item to ensure menu_icon is set
 					$query = $db->getQuery(true)
 						->update($db->quoteName('#__menu'))
-						->set($db->quoteName('params') . ' = ' . $db->quote($params))
-						->where($db->quoteName('id') . ' = ' . $existingId);
+						->set($db->quoteName('params') . ' = ' . $db->quote($mergedParams))
+						->where($db->quoteName('id') . ' = ' . (int) $existing->id);
 					$db->setQuery($query);
 					$db->execute();
 					continue;
@@ -422,6 +421,8 @@ class Pkg_MokoSuiteBackupInstallerScript
 					->getMVCFactory()
 					->createTable('Menu', 'Administrator');
 
+				$params = json_encode(['menu_icon' => $submenu['menu_icon']]);
+
 				$table->menutype     = $parent->menutype;
 				$table->title        = $submenu['title'];
 				$table->alias        = strtolower(str_replace(' ', '-', $submenu['title']));
@@ -443,7 +444,7 @@ class Pkg_MokoSuiteBackupInstallerScript
 					error_log('MokoSuiteBackup: Failed to create submenu "' . $submenu['title'] . '": ' . $table->getError());
 				}
 			}
-		} catch (\Throwable $e) {
+		} catch (\Exception $e) {
 			error_log('MokoSuiteBackup: ensureSubmenuItems() failed: ' . $e->getMessage());
 		}
 	}
@@ -464,12 +465,11 @@ class Pkg_MokoSuiteBackupInstallerScript
 					->update($db->quoteName('#__menu'))
 					->set($db->quoteName('img') . ' = ' . $db->quote($icon))
 					->where($db->quoteName('client_id') . ' = 1')
-					->where($db->quoteName('link') . ' LIKE ' . $db->quote('%com_mokosuitebackup%' . $linkFragment . '%'));
+					->where($db->quoteName('link') . ' LIKE ' . $db->quote('index.php?option=com_mokosuitebackup%' . $linkFragment . '%'));
 				$db->setQuery($query);
 				$db->execute();
 			}
 
-			// Set top-level component menu icon
 			$query = $db->getQuery(true)
 				->update($db->quoteName('#__menu'))
 				->set($db->quoteName('img') . ' = ' . $db->quote('class:archive'))
@@ -478,7 +478,7 @@ class Pkg_MokoSuiteBackupInstallerScript
 				->where($db->quoteName('level') . ' = 1');
 			$db->setQuery($query);
 			$db->execute();
-		} catch (\Throwable $e) {
+		} catch (\Exception $e) {
 			error_log('MokoSuiteBackup: syncMenuIcons() failed: ' . $e->getMessage());
 		}
 	}
@@ -517,8 +517,13 @@ class Pkg_MokoSuiteBackupInstallerScript
 				$db->setQuery($query);
 				$db->execute();
 			}
-		} catch (\Throwable $e) {
+		} catch (\Exception $e) {
 			error_log('MokoSuiteBackup: Could not restore download key: ' . $e->getMessage());
+			Factory::getApplication()->enqueueMessage(
+				'MokoSuiteBackup: Your download/license key could not be preserved during the update. '
+				. 'Please re-enter it in the Update Sites configuration to continue receiving updates.',
+				'warning'
+			);
 		}
 	}
 
@@ -554,7 +559,7 @@ class Pkg_MokoSuiteBackupInstallerScript
 				'warning'
 			);
 		}
-		catch (\Throwable $e) {
+		catch (\Exception $e) {
 			error_log('MokoSuiteBackup: License key check failed: ' . $e->getMessage());
 		}
 	}