LNK2022: Metadata Operation Failed (8013118D)

Using MFC and meet with this error

(__POSITION) Error ?

In MSDN ,it says that ,"This behavior occurs because the compiler generated incorrect metadata for these anonymous structures. "

and the Resolution is

"To resolve this problem, add unique identifiers when you use Managed Extensions for C++ so that you avoid using anonymous structures as global variables.

What does it mean by saying that?

Thx for help.

>What does it mean by saying that?
Can we see some code?