Assets/Vuforia/Scripts/DefaultInitializationErrorHandler.cs(10,7): error CS0246: The type or namespa

Assets/Vuforia/Scripts/DefaultInitializationErrorHandler.cs(10,7): error CS0246: The type or namespace name `Vuforia' could not be found. Are you missing an assembly reference?

换到unity2017打包的时候出现了这个错误，遍寻网络找不到原因。后来发现是这玩意没打开，打开就好了哈哈哈。