ASSERT ERROR when doing timing_driven placement

[JeffreyzzZ0]

Dear Prof @limbo018 , when I doing timing-driven placement with my own case, the OpenTimer seems failed to find net in timer.

and in the source code, timer seems to be running parallelly, so the assert error can report different failed net names. Does that mean the OpenTimer fail to read the def , lef, lib or any other files ?. And an error was found in the log. It seems that the open timer can only read one lib and one lef file, Is there any connection between them? I am very confused about this. Thanks for your help!