更改原理图后,进行正标,提示错误:there are errors .see logfile.BackAnnotation.txt.logfile中提示如下:presumably,this design has never been forword annotated in the ICDB environment.BackAnnotation can not proceed。 " |$ \+ b9 ^" O3 [3 u+ x' W请问一下,这是什么原因,应该怎么解决呢?谢谢! ; {8 m$ R% `0 e7 M L7 a" D4 F