将igs文件导入LT出现以下问题: p{4nWeH?B
?T <2Cl'C
*** Error (AITX_BLANKED_ENTS) *** .:=G=v=1
<C,lHt
The input file did not contain any supported non blanked independant entities. <mdHca
hUGP3ExC*
Please check the documentation for a list of supported entities. f+Ht
yJAz#~PO/
请教各位是什么原因,如何解决?