Single instance

By default fman runs as a single instance. Launching fman again while it is already running does not open a second window — the running instance handles the launch instead.

What happens on a second launch

Command	Result
fman "C:\some\folder"	The running fman comes to the front and opens the folder in the active pane
fman "C:\some\file.txt"	Opens the file's parent folder in the active pane, cursor on the file
fman	The running window is simply raised and focused
fman "C:\a" "C:\b"	The first path opens in the active pane, the next in the other pane, and so on

If no instance is running, fman starts normally.

Turning it off

To allow multiple independent fman windows, set single_instance to false in the app settings file:

<DataDirectory>/Local/Settings.json

{
  "single_instance": false
}

The default is true. Create the file if it does not exist.

If the connection between instances cannot be set up for any reason, fman just starts a normal instance instead — this never blocks startup.