The package 'MySql.Data' tried to add a framework reference to 'System.Runtime' which was not found in the GAC

最近在学习Visual Studio连接mysql EF模型。在nuget中安装mysql.data时总是提示The package 'MySql.Data' tried to add a framework reference to 'System.Runtime' which was not found in the GAC。当前mysql.data的版本是6.10.5，看描述是支持.net framework 4.5.2的。经过研究发现，把项目的.net framework 改为4.5可以安装成功。