'identifier' : no GUID has been associated with this object
The __uuidof operator can take either a user defined type with a GUID attached or an object of such a user defined type as its argument. This error occurs when the supplied argument is a user defined type, but without a GUID attached.
For example:
struct F {
};
struct __declspec(uuid("00000000-0000-0000-0000-000000000000")) F2 {
};
void bar(void)
{
__uuidof(F); // error C2787
__uuidof(F *); // error C2787
__uuidof(F2); // OK
}