Request for enlightenment on error messages

I continue to receive two error messages, and I can’t make sense of 'em. Any help would be appreciated.

  1. Whenever anyone calls via PSTN, I get the following: “Channel ‘zap 2-1’ sent into invalid extension ‘s’ in the context ‘default’ , but no invalid handler”

  2. When I reload, I get: “chan_zap.c:10879 setup_zap: Ignoring Signalling”

Many thanks,