When mining in the world or use TNT above and below ground this crash occurs. You can just run around exploring and the server will crash with this error without breaking any block.

java.security.InvalidParameterException: The gem redGarnet could not be found.
at techreborn.items.ItemGems.getGemByName(ItemGems.java:28)
at techreborn.items.ItemGems.getGemByName(ItemGems.java:32)
at techreborn.blocks.BlockOre.getDrops(BlockOre.java:92)
at techreborn.blocks.BlockOre.getDrops(BlockOre.java:36)
at net.minecraft.block.Block.func_180653_a(Block.java:557)
at net.minecraft.world.Explosion.func_77279_a(Explosion.java:231)
at net.minecraft.world.WorldServer.func_72885_a(WorldServer.java:1178)
at net.minecraft.world.World.func_72876_a(World.java:2282)
at net.minecraft.entity.item.EntityTNTPrimed.func_70515_d(SourceFile:98)
at net.minecraft.entity.item.EntityTNTPrimed.func_70071_h_(SourceFile:88)
at net.minecraft.world.World.func_72866_a(World.java:1987)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:840)
at net.minecraft.world.World.func_72870_g(World.java:1957)
at net.minecraft.world.World.func_72939_s(World.java:1773)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:621)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:720)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:384)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:624)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:482)
at java.lang.Thread.run(Thread.java:745)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Server thread
Stacktrace:
at techreborn.items.ItemGems.getGemByName(ItemGems.java:28)
at techreborn.items.ItemGems.getGemByName(ItemGems.java:32)
at techreborn.blocks.BlockOre.getDrops(BlockOre.java:92)
at techreborn.blocks.BlockOre.getDrops(BlockOre.java:36)
at net.minecraft.block.Block.func_180653_a(Block.java:557)
at net.minecraft.world.Explosion.func_77279_a(Explosion.java:231)
at net.minecraft.world.WorldServer.func_72885_a(WorldServer.java:1178)
at net.minecraft.world.World.func_72876_a(World.java:2282)
at net.minecraft.entity.item.EntityTNTPrimed.func_70515_d(SourceFile:98)
at net.minecraft.entity.item.EntityTNTPrimed.func_70071_h_(SourceFile:88)
at net.minecraft.world.World.func_72866_a(World.java:1987)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:840)
at net.minecraft.world.World.func_72870_g(World.java:1957)

-- Entity being ticked --
Details:
Entity Type: minecraft:tnt (net.minecraft.entity.item.EntityTNTPrimed)
Entity ID: 3241
Entity Name: Block of TNT
Entity's Exact location: 58.88, 63.07, 241.83
Entity's Block location: World: (58,63,241), Chunk: (at 10,3,1 in 3,15; contains blocks 48,0,240 to 63,255,255), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Entity's Momentum: 1.31, -0.50, 0.92
Entity's Passengers: []
Entity's Vehicle: ERROR NullPointerException: null
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1773)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:621)

Dupe of: #836
Update, its been fixed.

Thank you so much!