When you are in dev mode, tracy automatically starts session

[romanmatena]

So you every time get the error

[2018-02-28 18-49-44] Session is already started, please close it first and then you can disabled it.

but you can looking hours for the reason why, even if the session autoStart is set to false, the session is started by tracy

[woytam]

There is a PR#362 in Tracy about that.