Plugins without any MASTers set will get removed from the load order by the engine (at least Fallout4.exe, haven't tested with others). As such it might be nice for LOOT to show a warn or error either at the top or by individual plugins that do not have a MAST (at the very least if they're also active, but possibly even if not).

This should probably be tested for other engines as well.

Dummy Plugin.zip is an empty plugin for Fallout 4 without any MAST.