hfss仿真出现这个问题怎么回事？

错误提示如下：
    [error] Port refinement, process hf3d error: Too few conductors were found on port 1.  There should be one conductor for each terminal, with one additional reference
      conductor.  Unintentional contact between conductors may cause this error.. (11:18:34 上午  十一月 25, 2013)
    [error] Simulation completed with execution error on server: Local Machine. (11:18:34 上午  十一月 25, 2013)
求高人解答啊。