stack trace

bad argument #2 to '?' (index out of bound)
stack traceback:
        [C]: at 0x2b4f0352a7e0
        [C]: in function '__index'
        ./onmt/translate/Beam.lua:97: in function 'func'
        ./onmt/utils/Tensor.lua:12: in function 'recursiveApply'
        ./onmt/utils/Tensor.lua:7: in function '_indexState'
        ./onmt/translate/BeamSearcher.lua:171: in function '_retrieveHypothesis'
        ./onmt/translate/BeamSearcher.lua:230: in function '_completeHypotheses'
        ./onmt/translate/BeamSearcher.lua:74: in function 'search'
        ./onmt/translate/Translator.lua:313: in function 'translateBatch'
        ./onmt/translate/Translator.lua:402: in function 'translate'
        translate.lua:110: in function 'main'
        translate.lua:196: in main chunk
        [C]: in function 'dofile'
        ...lmia/torch/install/lib/luarocks/rocks/trepl/scm-1/bin/th:150: in main chunk
        [C]: at 0x00406670