The formatter wants you to put multiple entries on the same line like this:

"net.minecraft.event.HoverEvent$Action", "lotr.common.fac.LOTRFaction",
"lotr.common.quest.LOTRMiniQuestFactory", "lotr.common.world.map.LOTRWaypoint",
"lotr.common.world.map.LOTRWaypoint$Region", "lotr.common.world.spawning.LOTRInvasions",
"lotr.common.LOTRShields", "lotr.common.LOTRDimension$DimensionRegion",
"lotr.common.item.LOTRItemBanner$BannerType", "lotr.common.LOTRAchievement$Category",

It would be nice if you add what addon/version of lotr requires this,
Default lotr doesn't need it so I presume some modified version/addon needs it?

LOTR v36.14

Without these multiple entries, my client would not start at all.

I use lotr 36.14 without these and it works fine. What other mods do you use? If you use any lotr addons that's why it's not working, so the name of that addon should be added to the comment for clarity.
In my opinion this should also be done to the LOTRFaction listing as that's only needed when LOTweakR is used. I'll add a note at some point for that myself