This warning is reported when any treasure2 loot table is attempted to be spawned, and no loot is created:
[Server thread/WARN] [net.minecraft.world.storage.loot.LootTableManager]: Couldn't find resource table treasure2:loot_tables/treasure2/chests/scarce/general_chest

This can reproduced by using a command to add one of these tables to a chest:
/setblock ~ ~ ~ chest 0 {LootTable:"treasure2:loot_tables/treasure2/chests/scarce/general_chest"}

This is likely also why treasure2 loot tables cannot be used by recurrent complex.

Additionally, treasure2 chests do not spawn loot from any treasure tables added to nbt data in this way, even loot tables from vanilla minecraft.

Thank you for your time!

You can't access Treasure2 loot tables that way. Treasure2 has it's own Loot Table manager outside of vanilla.