'member' : '__declspec(modifier)' cannot be applied to this symbol

You cannot declare per-process or per-appdomain for static members of a managed class.

See appdomain for more information.

The following sample generates C2506.

// C2506.cpp
// compile with: /clr /c
ref struct R {
   __declspec(process) static int n;   // C2506
   int o;   // OK
};