解决unity中出现The type or namespace name `MySql' could not be found. Are you missing an assembly referen

unity报错解决unity中出现The type or namespace name `MySql' could not be found. Are you missing an assembly referen ：

错误原因：

Framework target is set to Mono/.NET 3.5, however in Unity 5.5 while loading this dll, the following error appears: "Plugin targets .NET 4.x and is marked as compatible with Editor. Editor can use assemblies targetting .NET 3.5 or lower, please unselect Editor as compatible platform."

Steps to reproduce:
1. Open User's attached project with Unity 5.5 or newer
2. See the Error in the Console

Result: "Serializer" dll fails to load with "Plugin targets .NET 4.x and is marked as compatible with Editor..." message.

Reproduced with: 2017.1.0a3, 5.6.0f1, 5.5.2p2.
Not reproduced with: 5.4.5f1.

Note:
dll loads successfully with Unity 5.4
target framework for each project is set to "Mono/.NET 3.5"

翻译：

框架目标被设置为Mono/。但是在加载这个dll时，在Unity 5中，出现了以下错误：“插件目标。NET 4。x并被标记为与编辑器兼容。编辑器可以使用程序集。NET 3.5或更低，请取消选择编辑器作为兼容的平台。

重现步骤:

1。开放用户附加的项目，有5。5或更新的

2。查看控制台中的错误

结果：“序列化器”dll不能加载“插件目标。NET 4”。x并被标记为与编辑器兼容。“消息。

复制：2017.1.0 a3，5.6.0，5。5.2 p2。

不复制:5.4.5f1。

注意:

dll在Unity 4中成功加载

每个项目的目标框架被设置为“Mono/。NET 3.5”

解决方案：

下载资源（mysql.data.dll和system.data.dll , system.drawing.dll）:

https://download.****.net/download/mengchenliuguang/10561119

1.以上三个文件下载后，将其投入到Assets中