MTF的警告不知道什么意思？

在用CODE V做光学设计练习的时候，发现把第四视场的R曲线的权重修改做优化后，再更新MTF曲线，发现不能显示了，出现了下面这样的警告，请问这是什么原因呢，怎么解决呢？
arning: No rays get through for field   1, wavelength  1. Check apertures.
             No rays get through for field   1, wavelength  2. Check apertures.
             No rays get through for field   1, wavelength  3. Check apertures.
             No rays get through for field   2, wavelength  1. Check apertures.
             No rays get through for field   2, wavelength  2. Check apertures.
             No rays get through for field   2, wavelength  3. Check apertures.
             No rays get through for field   3, wavelength  1. Check apertures.
             No rays get through for field   3, wavelength  2. Check apertures.
             No rays get through for field   3, wavelength  3. Check apertures.
             No rays get through for field   4, wavelength  1. Check apertures.
             No rays get through for field   4, wavelength  2. Check apertures.
             No rays get through for field   4, wavelength  3. Check apertures.
             No rays get through for field   5, wave