title: Meta Data File in Unity?
body: <p>I have just started learning unity and was just building a simple game but today when I just changed some code in a script. Unity started giving me this errors</p>
  <pre><code>Microsoft (R) Visual C# Compiler version 2.9.1.65535 (9d34608e)
  Copyright (C) Microsoft Corporation. All rights reserved.
  
  error CS0009: Metadata file 'C:\Program Files\Unity\Hub\Editor\2019.4.14f1\Editor\Data\Managed\UnityEngine\UnityEngine.ParticleSystemModule.dll' could not be opened -- Invalid assembly name: ''
  </code></pre>
  <p>I don't know what is this I restarted Unity and nothing happened</p>
  <p>Here is My File Hierarchy:</p>
  <pre><code>    Unity_Projects
           My First Game
                 .vscode
                     settings.json
                 Assets
                   Scenes
                      Nothing
                   FollowPlayer.cs
                   PlayerColiison.cs
                   PlayerMovement.cs
                   Slippery.physicMaterial
                Logs
                  Packages-Update.log
                Packages
                  manifest.json
                  packages-lock.json
                Assembly-CSharp.csproj
                My First Game.sln
  
  </code></pre>
  <p>I don't know that what is happening and I use VsCode because Visual Studio hangs my Machine
  If Anyone know this please tell me how to fix it</p>
  <p>Thanks For Helping!</p>