什么是sql72009错误？

我的数据库项目Visual Studio 2013中出现了以下许多错误。然而，我不再使用下面的DLL（我以前使用过它们，但我从引用中删除了它们）

所以我的问题是：

sql72009错误的确切含义是什么

什么时候发生

---

我只是在使用SQL Server数据工具时遇到了这个问题，在我的例子中，这个问题是一个循环依赖关系：两个函数相互引用。

可能是重复的

Error SQL72009: [Accessibility] has an unresolved dependency to 
[System.Windows.Forms]. A deployment script with correct ordering cannot be 
created.

Error SQL72009: [System.Design] has an unresolved dependency to [System.Web]. 
A deployment script with correct ordering cannot be created.

Error SQL72009: [System.Windows.Forms] has an unresolved dependency to 
[System.Web]. A deployment script with correct ordering cannot be created.

Error SQL72009: [System.Windows.Forms] has an unresolved dependency to 
[System.Design]. A deployment script with correct ordering cannot be created.

Error SQL72009: [System.Windows.Forms] has an unresolved dependency to 
[System.Drawing.Design]. A deployment script with correct ordering cannot be 
created.

Error SQL72009: [System.Windows.Forms] has an unresolved dependency to 
[Microsoft.Build.Tasks.v4.0]. A deployment script with correct ordering cannot 
be created.
....