Currently, all Scala serializers, e.g. OptionSerializer, CaseClassSerializer, TrySerializer etc. do not have the serialVersionUID specified.
In 1.3, the Scala serializer (all serializers in general) implementations had to be changed since implementation of the compatibility methods snapshotConfiguration, ensureCompatibility had to be implemented, resulting in a new serialVersionUID.
This means that when restoring from a snapshot pre-1.3 that contains Scala types as state, the previous serializer in the snapshot cannot be deserialized (due to UID mismatch).
To fix this, we should specify the serialVersionUIDs of the Scala serializers to be what they originally were pre-1.3. This would then allow users with Scala types as state to restore from older versions.