My project works fine with Boost 1.33.1 but when I want to make it with boost 1.42.0 I get several errors. In file included from /home/mahmood/boost_1_42_0/boost/multi_index_container_fwd.hpp:18,                  from /home/mahmood/boost_1_42_0/boost/multi_index_container.hpp:30,                  from BaseCacheControllerImpl.cpp:61: /home/mahmood/boost_1_42_0/boost/multi_index/indexed_by.hpp:61: error: wrong number of template arguments (50, should be 20) /home/mahmood/boost_1_42_0/boost/mpl/aux_/preprocessed/gcc/vector.hpp:22: error: provided for ‘template struct boost::mpl::vector’ In file included from /home/mahmood/boost_1_42_0/boost/multi_index/detail/ord_index_args.hpp:21,                  from /home/mahmood/boost_1_42_0/boost/multi_index/ordered_index_fwd.hpp:16,                  from /home/mahmood/boost_1_42_0/boost/multi_index_container_fwd.hpp:19,                  from /home/mahmood/boost_1_42_0/boost/multi_index_container.hpp:30,                  from BaseCacheControllerImpl.cpp:61: /home/mahmood/boost_1_42_0/boost/multi_index/tag.hpp:79: error: wrong number of template arguments (50, should be 20) /home/mahmood/boost_1_42_0/boost/mpl/aux_/preprocessed/gcc/vector.hpp:22: error: provided for ‘template struct boost::mpl::vector’ /home/mahmood/boost_1_42_0/boost/multi_index/tag.hpp:81: error: template argument 1 is invalid What happend to the indexed_by.hpp from 1.33.1 to 1.42.0. All ideas are welcomed.   // Naderan *Mahmood;