Issue description:
crash on breaking smeltery ladder to fully destroy a smeltery not just shrink size

If crashed, link to crash report (use a site such as pastebin):
14:05:48.461
net.minecraft.util.concurrent.ThreadTaskExecutor
Server thread
Error executing task on Server
java.lang.NullPointerException
at net.minecraftforge.common.util.LazyOptional.lambda$invalidate$1(LazyOptional.java:335)
at net.minecraftforge.common.util.LazyOptional$$Lambda$23235/1988412364.accept(Unknown Source)
at java.lang.Iterable.forEach(Iterable.java:75)
at net.minecraftforge.common.util.LazyOptional.invalidate(LazyOptional.java:335)
at slimeknights.tconstruct.smeltery.tileentity.MelterTileEntity.invalidateCaps(MelterTileEntity.java:112)
at net.minecraft.tileentity.TileEntity.func_145843_s(TileEntity.java:143)
at net.minecraft.world.chunk.Chunk.func_177425_e(Chunk.java:449)
at net.minecraft.world.World.func_175713_t(World.java:662)
at net.minecraft.block.AbstractBlock.func_196243_a(AbstractBlock.java:136)
at slimeknights.mantle.block.InventoryBlock.func_196243_a(InventoryBlock.java:131)
at net.minecraft.block.AbstractBlock$AbstractBlockState.func_196947_b(AbstractBlock.java:616)
at net.minecraft.world.chunk.Chunk.func_177436_a(Chunk.java:267)
at net.minecraft.world.World.func_241211_a_(World.java:199)
at net.minecraft.world.World.func_180501_a(World.java:176)
at net.minecraftforge.common.extensions.IForgeBlock.removedByPlayer(IForgeBlock.java:200)
at net.minecraftforge.common.extensions.IForgeBlockState.removedByPlayer(IForgeBlockState.java:157)
at net.minecraft.server.management.PlayerInteractionManager.removeBlock(PlayerInteractionManager.java:271)
at net.minecraft.server.management.PlayerInteractionManager.func_180237_b(PlayerInteractionManager.java:254)
at net.minecraft.server.management.PlayerInteractionManager.func_229860_a_(PlayerInteractionManager.java:220)
at net.minecraft.server.management.PlayerInteractionManager.func_225416_a(PlayerInteractionManager.java:190)
at net.minecraft.network.play.ServerPlayNetHandler.func_147345_a(ServerPlayNetHandler.java:929)
at net.minecraft.network.play.client.CPlayerDiggingPacket.func_148833_a(SourceFile:40)
at net.minecraft.network.play.client.CPlayerDiggingPacket.func_148833_a(SourceFile:10)
at net.minecraft.network.PacketThreadUtil.func_225383_a(SourceFile:21)
at net.minecraft.network.PacketThreadUtil$$Lambda$21937/1224358368.run(Unknown Source)
at net.minecraft.util.concurrent.TickDelayedTask.run(SourceFile:18)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213166_h(SourceFile:144)
at net.minecraft.util.concurrent.RecursiveEventLoop.func_213166_h(SourceFile:23)
at net.minecraft.server.MinecraftServer.func_213166_h(MinecraftServer.java:734)
at net.minecraft.server.MinecraftServer.func_213166_h(MinecraftServer.java:159)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213168_p(SourceFile:118)
at net.minecraft.server.MinecraftServer.func_213205_aW(MinecraftServer.java:717)
at net.minecraft.server.MinecraftServer.func_213168_p(MinecraftServer.java:711)
at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213160_bf(SourceFile:103)
at net.minecraft.server.MinecraftServer.func_213202_o(MinecraftServer.java:696)
at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:646)
at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232)
at net.minecraft.server.MinecraftServer$$Lambda$20440/1002772234.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Versions:

• Minecraft:1.16.5
• Forge: 36.1.32
• Mantle: 1.6.109
• Tinkers Construct: 3.0.4.179

Confirm below that this issue is not covered on the roadmap or "Whats New?"
?
Can it be reproduced with just Tinkers Construct? If not, list the other mods required to reproduce the issue.
?
Should be fewer than 10 mods, you should be running no mods besides those 10 when you reproduce the issue.

Closing for lack of response. Looking at the code this issue should be impossible unless someone adds an invalid capability listener

? is not a valid answer, and you ignored the instructions on how to add your crash report. Actually follow the instructions so we have a full crash report.