Status: the dicom reader code generates two unspupported properties associated with the loaded image
They are generated in mitk::DICOMImageBlockDescriptor::DescribeImageWithProperties(). In both cases the property stores an enum defined in mitkDICOMEnums.h (e.g. GenericProperty<PixelSpacingInterpretation>), but those template instaces have no registered property serializer. Thus an error/warning is caused when serializing sessions with loaded DICOM files and both properties are silently dropped.
I think it is not a critical bug, because the dropped properties are normaly not used. But it is irritating for users because the see an error message when saving a scene and might think something is realy corrupted.
Clean solution would be to introduce also property serializer for the used GenericProperty types (or maybe that information is dropped in context of T25307).