求助，Maxwell不能plot mash

我对转子运动区域band划分网格，划分网格后plot mash，但是提醒Plot 'Mesh1' becomes invalid due to no available mesh.
定子的求解区域就可以正常划分，其他区域也是。    

我是最后求解时出现错误：Maxwell2d solver, process solver2d error: Internal Solver Error:  'Force/torque can not be calculated well inside the moving parts! The enclosing object (band subtracted by moving objects) might not have triangles. Make sure that there is at least one layer of elements around the moving objects which belong to the band object!'.
好像是网格划分问题，每个区域分别plot mash，除了转子运动求解区域之外所有区域都能plot mash，转子运动求解区域提示是Plot 'Mesh1' becomes invalid due to no available mesh。好像就是这导致求解错误，但是不知道怎么解决，也不知道是怎么产生的