Error Handling Nodes
Unfortunately, when dealing with network operations, errors are always a possibility and game should handle them gracefully. Perhaps the host of the session you try to join has just quit a moment earlier, or perhaps your internet service went down temporarily, or any number of other problems occur. Through Blueprints, your games have more flexibility in how they handle these network-related errors.
Failures that originate from the Session Operations described above will be reported through the OnFailure execution pin, so you can set up your game to handle these failures as you wish. For certain kinds of failures however, or failures that occur in the middle of gameplay, there are a couple of Error Events that can be called within a GameInstance Blueprint, Network Error and Travel Error.