Hello and thanks for the help I received so far.
here is my current problem:

The class I try to serialize is:

class LIBPALO_NG_CLASS_EXPORT CubeCache : public CUBE_INFO {
        public:
            friend class boost::serialization::access;
            CubeCache();
            ~CubeCache();

            void setSequenceNumber( unsigned int sequenceNumber ) {
                m_SequenceNumber = sequenceNumber;
            }

            unsigned int getSequenceNumber() const {
                return m_SequenceNumber;
            }

        private:
            unsigned int m_SequenceNumber;
            template<class Archive>
            void serialize( Archive &ar, const unsigned int version );
           
        };

the cpp file looks as follows:

#include "CubeCache.h"
#include <boost/serialization/base_object.hpp>
namespace jedox {
    namespace palo                 /* palo */
    {
        template<class Archive>
        void CubeCache::serialize( Archive &ar, const unsigned int version ) {
            // save/load base class information
            ar & boost::serialization::base_object<CUBE_INFO>( *this );
            ar & m_SequenceNumber;
        }
       
        CubeCache::CubeCache(){;}
        CubeCache::~CubeCache(){;}
    }
}                                 /* jedox */

The CUBE_INFO structure serializes just fine. There are no linkage problems with the following code:

int main( int argc, char* argv[] ) {
      CUBE_iNFO* const c = new CUBE_INFO();
    std::ofstream ofs("filename");
    // save data to archive
    {
        boost::archive::text_oarchive oa( ofs );
        // write class instance to archive
        oa << ( c );
        // archive and stream closed when destructors are called
    }
    return 0;
}

However, when I use CubeCache instead of CUBE_INFO in the above code, i get a linkage error:
======================================================================
libpalo_ng.obj : error LNK2019: unresolved external symbol "private: void __thiscall jedox::palo::CubeCache::serialize<class boost::archive::text_oarchive>(class boost::archive::text_oarchive &,unsigned int)"  ...
======================================================================

There are no linkage problems with the library when i do not use boost::serialization. I guess this happens
when the linker tries to link with the serialization library. LIBPALO_NG_CLASS_EXPORT is defined as:
#   define LIBPALO_NG_CLASS_EXPORT __declspec(dllexport)
Regards, Oliver