Compiler Error C2367

'symbol' : redefinition; different uuid specified

The object is multiply declared with a different GUID each time. For example:

struct __declspec(uuid("{00000000-0000-0000-C000-000000000046}")) IUnknown;
struct __declspec(uuid("{00000000-0000-0000-C000-000000000047}")) IUnknown{};