Getting an "Unknown error" in MSTeams botFframework while sending message in Teams.

While, i am trying to send any message in bot, it responds with an "Unknown error". i am not able to understand in which  scenarios it responds with such error.
 I have tried after deleting the team, if i try to send message using botFramework it responds with two types of error randomly "Conversation not found" and "Unknown error".

In which scenarios i'll get "Unknown error"?

Is there a way to identify if the team is deleted ?