FTBLib: 5.4.1.99
YABBA: 1.1.2.51

Open Modular Passive Defense recently released an overhaul for their mods and it seems that OMPD hardened blocks stored in YABBA barrels are now causing a TE crash on world load with:

[Server thread/WARN] [net.minecraft.util.datafix.walkers.BlockEntityTag]: Unable to resolve BlockEntity for ItemInstance: yabba:item_barrel

Debug Section: https://pastebin.com/MLkrRScQ
Crashlog: https://pastebin.com/dxYgq2VR
OMPD Issue: OpenModularTurretsTeam/OpenModularPassiveDefense#25

OMPD Dev here. Why is the tile entities internal name even used when stored in barrels?

/edit: nvm, there seems to be something else going on in YABBA.

I think I know what the issue is. If barrel has item inside and its broken it drops ItemStack with NBT tag BlockEntityTag. You can get the same item if you hold control and middle-click/pick block, except that one will also have id tag, which I don't add. For some reason this doesn't work here, it always has before

Updated to FTBLib 5.4.3.103 still getting the same errors and crash

Edit: Scratch that. Loaded up a save backup and it worked first go now. Looks like the initial compat issue between the 2 mods corrupted the world. So I believe the issue is now fixed. Thanks to both.