Gambit划分体网格的问题

各位大神你们好，小弟在用Gambit前处理之后在进行file---export---mesh输出3D网格文件的时候出现了一次错误：all mesh nodes must lie on the xy plane or a parallel plane within tolerance .errors were found during export. export file was not created.这个问题困扰我整整两天了，被闷死了，求大神指导解决，不胜感激。