“The dll is not allowed to be included or could not be found” while building."解决办法
https://docs.unity3d.com/Manual/dotnetProfileAssemblies.html
1：删除掉工程中的System.Windows.Forms.dll等文件
2：切换 .NET Standard 2.0 ->.NET 4.x
3：Asset 目录下添加 mcs.rsp/csc.rsp文件，文件内容 " -r:System.Windows.Forms.dll "
4:重启Unity
