More than likely this is a EU2 issue but with so many open issues for EU2 and how little attention the bugs are given I am submitting here as well just in case there is something that can be done on the silent's gems side. If nothing can be done this can be closed.

Versions

Minecraft Version: 1.12.2
Silent's Gems Version: SilentsGems-1.12-2.6.5-256
Silent Lib Version: SilentLib-1.12-2.2.16-97
Modpack and Version (if applicable): EOD:Synthesis 1.2.3

Expected behavior

Fortune 3 on a pickaxe causes extra drops when used to right click harvest crops, red orchid redstone, etc. I have setup an automated method of getting redstone with a redorchid and mechanical users pointed at it. Next step is to place a fortune3 item, in my case a spare pickaxe I had stopped using, so it will get more drops. This works when held by the player and I get ~4 redstone per right click vs 1 when the mechanical user does it without a fortune3 item.

Actual behaviour

Using a supercharged silentsgems pickaxe with fortune 3 on it in a mechanical user from EU2 configured to "use item on entity" causes the world to crash with:
Error while interacting with block extrautils2:redorchid[growth=0] with 1xitem.silentgems:Pickaxe@849

-----------------------CRASH LOG SNIP---------------------------
Description: Ticking block entity

java.lang.RuntimeException: Error while interacting with block extrautils2:redorchid[growth=0] with 1xitem.silentgems:Pickaxe@849. Method:ACTIVATE_BLOCK_WITH_ITEM Button:RIGHT_CLICK
at com.rwtema.extrautils2.tile.TileUse.operate(TileUse.java:289)
at com.rwtema.extrautils2.tile.TileAdvInteractor.func_73660_a(TileAdvInteractor.java:93)
at net.minecraft.world.World.func_72939_s(World.java:1829)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:612)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:765)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:666)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:185)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:524)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at sorazodia.survival.mechanics.PlayerActionEvent.blockRightClick(PlayerActionEvent.java:134)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_1608_PlayerActionEvent_blockRightClick_RightClickBlock.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:179)
at net.minecraftforge.common.ForgeHooks.onRightClickBlock(ForgeHooks.java:1102)
at com.rwtema.extrautils2.compatibility.BlockCompat.onRightClickBlock(BlockCompat.java:42)
at com.rwtema.extrautils2.tile.TileUse.operate(TileUse.java:217)
... 8 more

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

-- Head --
Thread: Server thread
Stacktrace:
at com.rwtema.extrautils2.tile.TileUse.operate(TileUse.java:289)
at com.rwtema.extrautils2.tile.TileAdvInteractor.func_73660_a(TileAdvInteractor.java:93)

-- Block entity being ticked --
Details:
Name: xu2:tileuse // com.rwtema.extrautils2.tile.TileUse
Block type: ID #293 (tile.extrautils2:user // com.rwtema.extrautils2.blocks.BlockAdvInteractor.Use)
Block data value: 3 / 0x3 / 0b0011
Block location: World: (-1884,69,532), Chunk: (at 4,4,4 in -118,33; contains blocks -1888,0,528 to -1873,255,543), Region: (-4,1; contains chunks -128,32 to -97,63, blocks -2048,0,512 to -1537,255,1023)
Actual block type: ID #293 (tile.extrautils2:user // com.rwtema.extrautils2.blocks.BlockAdvInteractor.Use)
Actual block data value: 3 / 0x3 / 0b0011
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1829)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:612)
-----------------------CRASH LOG SNIP---------------------------

Steps to reproduce the problem

1. Place redstone ore with redorchid on top
2. face mechanical user towards red orchid and put silent's gem pickaxe inside
3. Configure mechanical user for "activate block with item"
4. when redorchid grows world hangs and crashes on startup

I saw that as well and shrugged and moved on. A quick google search turned this up: https://github.com/SoraZodia/Survival-Tweaks
https://minecraft.curseforge.com/projects/survival-tweaks

One thing that sticks out is the line with "sorazodia.survival.mechanics", what mod is that?

Looks like it needs to be fixed in Survival Tweaks. Everything works with just Gems and EU2.