Using Lanterns on Slabs and Checking Mod Compatibility
Lantern Placement
Lanterns can be placed on half slabs the same way torches can. Aim at the top face of the slab and right-click with the lantern in hand. The lantern will sit on the slab at the proper height. This is useful for low ceilings, garden paths, and detailed builds where a full block would look too bulky.
Compatibility With Other Mods
The mod is designed to be compatible with slabs from other mods, and specific compatibility has been noted for Druidcraft and Upgrade Aquatic. Keep in mind that compatibility depends on which Minecraft version you are running. Older versions of those mods may not yet support the newer Minecraft release, so a slab from one of them might not accept a torch until both mods are updated for the same version.
If a Slab Won't Accept a Torch
First confirm the block is a half slab and not a full block, stair, or other shape. If it is a slab and still refuses, the other mod may not be updated to match your game version.