Specctra/PCAD 2002 error message

[jonperk]

I am trying to autoroute a PCAD 2002 design using Specctra 10.0.1. When starting the autorouter, I get the following message:


<<ERROR:>> Unrecognized Layer BOT
<ERROR:>> Error in file .\870_1.DSN, line 2941: token 5 = BOT
(content): (circuit (use_layer BOT))

This design has routed before, under a different file name. Does anyone have any ideas?

Thanks,

Jon