Why does it say no active sessions when I start the simulator?

When you see the message “No active sessions”, it simply means that no other simulator sessions are currently running. You are clear to start a new simulation session.

If you already have an active simulation running, the session manager will display the name of the model currently in use. This serves as a warning that if you proceed, the existing session (for example, a Brain simulation) will be closed so that a new session with a different model can be started.