So I must have followed old or incorrect instructions years ago when I set up domain mapping.
I have the file in mu-plugins, and I see now on the installation page that isn't right. My settings won't save when I change them so I know I need the new update.
If I install it properly, and network activate, what will happen to all the settings that are in place from the plugin being in mu-plugins? Will they sill be there?
Should I remove the plugin from mu-plugins before or after I network activate (as it should have been done)?