calibreview 后仿出现错误

最近在做VCO，后仿提取calibreview,用ADE进行后仿时出现了下面的错误，error found by spectre during hierarchy flattening.an instance of rfnmos_1p8 needs at least 4 terminals(but has only 0).请问各位大侠，这个错误是怎么回事呢?应该怎么改呢，谢谢啦。

求助！