add ComposerServiceProvider.php for view

app/Providers/ComposerServiceProvider.php

+<?php
+
+namespace App\Providers;
+
+use View;
+use Illuminate\Support\ServiceProvider;
+
+class ComposerServiceProvider extends ServiceProvider
+{
+    public function boot()
+    {
+        View::composer(
+            [
+                'admin.index',
+                'admin.uc.leftmenu',
+                'admin.uc.header'
+            ],
+            'App\Http\ViewComposers\LeftMenuComposer'
+        );
+    }
+
+    public function register()
+    {
+        //
+    }
+}

config/app.php

         App\Providers\EventServiceProvider::class,
         App\Providers\RouteServiceProvider::class,
 
+        /*
+         * Custom Service Providers...
+         */
+        App\Providers\ComposerServiceProvider::class,
     ],
 
     /*