Unity2018.3.X使用vscode出现.NET Framework,Version=v4.5 were not found.( OmniSharp in VS Code error)

问题描述：

vscode运行，出现如下：

The reference assemblies for framework ".NETFramework,Version=v4.5" were not found. To resolve this, install the SDK or Targeting Pack for this framework version or retarget your application to a version of the framework for which you have the SDK or Targeting Pack installed. Note that assemblies will be resolved from the Global Assembly Cache (GAC) and will be used in place of reference assemblies. Therefore your assembly may not be correctly targeted for the framework you intend.

（影响：vscode不智能提示）

解决方式：

1.在官网下载.NET Framework4.5.2(地址：https://dotnet.microsoft.com/download/thank-you/net452-developer-pack)并且安装。

2.找到.NET Framework4.5.2的安装目录：C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework

3.找到v4.5.2的文件夹，然后重命名文件夹为v4.5，就能解决不能智能提示的问题.

查看资料：https://github.com/Unity-Technologies/vscode-unity-debug/issues/115