Since List Fields is a Lotus Notes-based tool, it need to make Lotus Notes aware of its presence. This is mainly done via one key and value in the main configuration file of Lotus Notes; NOTES.INI. This change can be done without stopping Lotus Notes on it's own, but, if you run a previous version of List Fields, a component of List Fields will be loaded in memory by Lotus Notes at startup, and thus held by Lotus Notes. This means that the installer can't re-install the file, since it's already "active". Below you see how such as message would look:
The only remedy is to stop Lotus Notes first. In addition, even if the installer where able to replace files during the install process, Lotus Notes would have to restart in order to show you the menu item for List Fields. So, you're in for a restart of List Fields almost anyway!
If Lotus Notes is active when you install List Fields, you will see this screen:
You can either stop Lotus Notes itself, and click Next, or - you can click on the Stop Notes button. The Stop Notes button will try to close Lotus Notes gracefully. You'll see this message:
However, if you have any documents that need attention in Notes, where dialog boxes such as "Do you want to save this document" popup, this close-command will fail.
You should to check that Lotus Notes really stopped before you continue.