Teams Bot App debugging locally Listener function unable to start error

Copper Contributor



I have used the following guide to set up a Teams bot with Cron trigger to test out the abilities of the Teams Development toolkit. Debug your Teams app locally using Visual Studio - Teams | Microsoft Learn


I followed each step and all was well until the end when attempting to debug locally the function app could not fire its cron trigger and printed out the error "The listener for function 'NotifyTimerTrigger' was unable to start" and "No connection could be made because the target machine actively refused it. ("



I haven't been able to find anything I did wrong or others who have had this same issue. Any guidance would be appreciated.

2 Replies

Could you check if below points are causing this issue for you. 

  1. Firewall Settings: Verify that the firewall on both the local and target machine is not blocking the connection. You may need to add an exception for the specific port you're trying to use.
  2. Port Configuration: Make sure that the port you're trying to connect to is open and listening on the target machine.
Could you please let us know if you are still facing this issue?