Do you have the same problem if your destructor is not pure virtual?
Yes, it still asserts if the base class destructor is virtual rather than pure-virtual.
As a side note, why is this destructor pure virtual, rather than just be virtual? Are you trying to make your class not be instantiable directly, but only be instantiable from a derived class? In that case, simply make your constructors protected.
Yes, it is pure-virtual to prevent direct instantiation. Adding a constructor definition and making it protected just seems like a more obfuscated, verbose way of achieving the same result. It isn't even the same result either. With the protected constructor method, someone could still add a friend later on which could instantiate a Serializable object directly.