cadence layout 调instance 没响应

用着用着 调用instance 突然就不起作用了。
症状是：
调用某些库的元件的时候就没响应了，有时候又没问题。
提示的错误语句是：
*Error* putprop : first arg must be either symbol, list, defstruct or user type - nil
谢谢。

How you fix it?
when I do PSS simulation, I also have the same problem

Reboot "icfb" can solve my probelm.
I can't sure if yours could be solved,
because I don't know what you said by mentioning PSS simulation.