Your mod is doing something weird to the loot tables.
Mineshafts, strongholds, endcities, rooms with a spawner, these chests are completely emptied. I expect its due to a loot table null pointer exception, but I can't be certain because twitch fails me to give details.

Minecraft version: 1.14.4
Forge version: forge-28.1.111
modpack, something custom send by a friend.
Evidence of this bug:
[Client thread/ERROR]: Couldn't parse loot table minecraft:chests/abandoned_mineshaft java.lang.RuntimeException: Attempted to add a duplicate pool to loot table: dothack_inject at net.minecraft.world.storage.loot.LootTable.addPool(LootTable.java:237) ~[?:?] at mod.azure.wowweapons.util.LootHandler.lootLoad(LootHandler.java:36) ~[?:0.1.0] at net.minecraftforge.eventbus.ASMEventHandler_16_LootHandler_lootLoad_LootTableLoadEvent.invoke(.dynamic) ~[?:?] at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:80) ~[eventbus-1.0.0-service.jar:?] at net.minecraftforge.eventbus.EventBus.post(EventBus.java:258) ~[eventbus-1.0.0-service.jar:?] at net.minecraftforge.event.ForgeEventFactory.loadLootTable(ForgeEventFactory.java:629) ~[?:?] at net.minecraftforge.common.ForgeHooks.loadLootTable(ForgeHooks.java:831) ~[?:?] at net.minecraft.world.storage.loot.LootTableManager.lambda$apply$0(LootTableManager.java:47) [?:?] at net.minecraft.world.storage.loot.LootTableManager$$Lambda$5309/1700488119.accept(Unknown Source) [?:?] at java.util.HashMap.forEach(HashMap.java:1280) [?:1.8.0_51] at net.minecraft.world.storage.loot.LootTableManager.func_212853_a_(LootTableManager.java:44) [?:?] at net.minecraft.world.storage.loot.LootTableManager.func_212853_a_(LootTableManager.java:24) [?:?] at net.minecraft.client.resources.ReloadListener.func_215269_a(SourceFile:13) [?:?] at net.minecraft.client.resources.ReloadListener$$Lambda$3564/1852527981.accept(Unknown Source) [?:?] at java.util.concurrent.CompletableFuture.uniAccept(CompletableFuture.java:656) [?:1.8.0_51] at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:632) [?:1.8.0_51] at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442) [?:1.8.0_51] at net.minecraft.resources.AsyncReloader.func_219557_a(SourceFile:71) [?:?] at net.minecraft.resources.AsyncReloader$$Lambda$4154/1030048250.run(Unknown Source) [?:?] at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213166_h(SourceFile:144) [?:?] at net.minecraft.util.concurrent.RecursiveEventLoop.func_213166_h(SourceFile:23) [?:?] at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213168_p(SourceFile:118) [?:?] at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213161_c(SourceFile:127) [?:?] at jeresources.util.LootTableHelper.getManager(LootTableHelper.java:167) [?:0.10.0.70] at jeresources.compatibility.minecraft.MinecraftCompat.registerVanillaMobs(MinecraftCompat.java:42) [?:0.10.0.70] at jeresources.compatibility.minecraft.MinecraftCompat.init(MinecraftCompat.java:33) [?:0.10.0.70] at jeresources.compatibility.Compatibility.init(Compatibility.java:26) [?:0.10.0.70] at jeresources.proxy.CommonProxy.initCompatibility(CommonProxy.java:14) [?:0.10.0.70] at jeresources.jei.JEIConfig.registerCategories(JEIConfig.java:71) [?:0.10.0.70] at mezz.jei.load.PluginLoader.lambda$new$2(PluginLoader.java:108) [?:6.0.0.27] at mezz.jei.load.PluginLoader$$Lambda$6314/1558590331.accept(Unknown Source) [?:6.0.0.27] at mezz.jei.load.PluginCaller.callOnPlugins(PluginCaller.java:26) [?:6.0.0.27] at mezz.jei.load.PluginLoader.<init>(PluginLoader.java:108) [?:6.0.0.27] at mezz.jei.startup.JeiStarter.start(JeiStarter.java:71) [?:6.0.0.27] at mezz.jei.startup.ClientLifecycleHandler.onRecipesLoaded(ClientLifecycleHandler.java:127) [?:6.0.0.27] at mezz.jei.startup.ClientLifecycleHandler.lambda$new$2(ClientLifecycleHandler.java:104) [?:6.0.0.27] at mezz.jei.startup.ClientLifecycleHandler$$Lambda$4476/549679499.accept(Unknown Source) [?:6.0.0.27] at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:212) [eventbus-1.0.0-service.jar:?] at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:204) [eventbus-1.0.0-service.jar:?] at net.minecraftforge.eventbus.EventBus$$Lambda$1993/1410901593.invoke(Unknown Source) [eventbus-1.0.0-service.jar:?] at net.minecraftforge.eventbus.EventBus.post(EventBus.java:258) [eventbus-1.0.0-service.jar:?] at net.minecraftforge.client.ForgeHooksClient.onRecipesUpdated(ForgeHooksClient.java:1018) [?:?] at net.minecraft.client.network.play.ClientPlayNetHandler.func_199525_a(ClientPlayNetHandler.java:1268) [?:?] at net.minecraft.network.play.server.SUpdateRecipesPacket.func_148833_a(SourceFile:28) [?:?] at net.minecraft.network.play.server.SUpdateRecipesPacket.func_148833_a(SourceFile:15) [?:?] at net.minecraft.network.PacketThreadUtil.func_225383_a(SourceFile:21) [?:?] at net.minecraft.network.PacketThreadUtil$$Lambda$6234/1891947650.run(Unknown Source) [?:?] at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213166_h(SourceFile:144) [?:?] at net.minecraft.util.concurrent.RecursiveEventLoop.func_213166_h(SourceFile:23) [?:?] at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213168_p(SourceFile:118) [?:?] at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213160_bf(SourceFile:103) [?:?] at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:861) [?:?] at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:384) [?:?] at net.minecraft.client.main.Main.main(SourceFile:155) [?:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_51] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_51] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_51] at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_51] at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:56) [forge-1.14.4-28.1.111.jar:28.1] at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$409/1292325833.call(Unknown Source) [forge-1.14.4-28.1.111.jar:28.1] at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) [modlauncher-4.1.0.jar:?] at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) [modlauncher-4.1.0.jar:?] at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) [modlauncher-4.1.0.jar:?] at cpw.mods.modlauncher.Launcher.run(Launcher.java:81) [modlauncher-4.1.0.jar:?] at cpw.mods.modlauncher.Launcher.main(Launcher.java:65) [modlauncher-4.1.0.jar:?] [Client thread/ERROR]: Exception caught during firing event: Attempted to add a duplicate pool to loot table: dothack_inject Index: 2 Listeners: 0: NORMAL 1: ASM: class mod.azure.dothack.util.LootHandler lootLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 2: ASM: class mod.azure.wowweapons.util.LootHandler lootLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 3: ASM: class xxrexraptorxx.cdl.utils.Events lootTableLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 4: ASM: class cursedflames.bountifulbaubles.common.loot.LootTableInjector onLootTableLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 5: ASM: class vazkii.botania.common.core.loot.LootHandler lootLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 6: ASM: vazkii.quark.tools.module.AncientTomesModule@4245f469 onLootTableLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 7: ASM: de.teamlapen.vampirism.world.loot.LootHandler@6f587689 onLootLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 8: ASM: vazkii.quark.vanity.module.ColorRunesModule@7f788089 onLootTableLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V 9: LOWEST 10: ASM: class ovh.corail.tombstone.event.EventHandler onLootTableLoad(Lnet/minecraftforge/event/LootTableLoadEvent;)V java.lang.RuntimeException: Attempted to add a duplicate pool to loot table: dothack_inject at net.minecraft.world.storage.loot.LootTable.addPool(LootTable.java:237) at mod.azure.wowweapons.util.LootHandler.lootLoad(LootHandler.java:36) at net.minecraftforge.eventbus.ASMEventHandler_16_LootHandler_lootLoad_LootTableLoadEvent.invoke(.dynamic) at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:80) at net.minecraftforge.eventbus.EventBus.post(EventBus.java:258) at net.minecraftforge.event.ForgeEventFactory.loadLootTable(ForgeEventFactory.java:629) at net.minecraftforge.common.ForgeHooks.loadLootTable(ForgeHooks.java:831) at net.minecraft.world.storage.loot.LootTableManager.lambda$apply$0(LootTableManager.java:47) at net.minecraft.world.storage.loot.LootTableManager$$Lambda$5309/1700488119.accept(Unknown Source) at java.util.HashMap.forEach(HashMap.java:1280) at net.minecraft.world.storage.loot.LootTableManager.func_212853_a_(LootTableManager.java:44) at net.minecraft.world.storage.loot.LootTableManager.func_212853_a_(LootTableManager.java:24) at net.minecraft.client.resources.ReloadListener.func_215269_a(SourceFile:13) at net.minecraft.client.resources.ReloadListener$$Lambda$3564/1852527981.accept(Unknown Source) at java.util.concurrent.CompletableFuture.uniAccept(CompletableFuture.java:656) at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:632) at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442) at net.minecraft.resources.AsyncReloader.func_219557_a(SourceFile:71) at net.minecraft.resources.AsyncReloader$$Lambda$4154/1030048250.run(Unknown Source) at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213166_h(SourceFile:144) at net.minecraft.util.concurrent.RecursiveEventLoop.func_213166_h(SourceFile:23) at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213168_p(SourceFile:118) at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213161_c(SourceFile:127) at jeresources.util.LootTableHelper.getManager(LootTableHelper.java:167) at jeresources.compatibility.minecraft.MinecraftCompat.registerVanillaMobs(MinecraftCompat.java:42) at jeresources.compatibility.minecraft.MinecraftCompat.init(MinecraftCompat.java:33) at jeresources.compatibility.Compatibility.init(Compatibility.java:26) at jeresources.proxy.CommonProxy.initCompatibility(CommonProxy.java:14) at jeresources.jei.JEIConfig.registerCategories(JEIConfig.java:71) at mezz.jei.load.PluginLoader.lambda$new$2(PluginLoader.java:108) at mezz.jei.load.PluginLoader$$Lambda$6314/1558590331.accept(Unknown Source) at mezz.jei.load.PluginCaller.callOnPlugins(PluginCaller.java:26) at mezz.jei.load.PluginLoader.<init>(PluginLoader.java:108) at mezz.jei.startup.JeiStarter.start(JeiStarter.java:71) at mezz.jei.startup.ClientLifecycleHandler.onRecipesLoaded(ClientLifecycleHandler.java:127) at mezz.jei.startup.ClientLifecycleHandler.lambda$new$2(ClientLifecycleHandler.java:104) at mezz.jei.startup.ClientLifecycleHandler$$Lambda$4476/549679499.accept(Unknown Source) at net.minecraftforge.eventbus.EventBus.doCastFilter(EventBus.java:212) at net.minecraftforge.eventbus.EventBus.lambda$addListener$11(EventBus.java:204) at net.minecraftforge.eventbus.EventBus$$Lambda$1993/1410901593.invoke(Unknown Source) at net.minecraftforge.eventbus.EventBus.post(EventBus.java:258) at net.minecraftforge.client.ForgeHooksClient.onRecipesUpdated(ForgeHooksClient.java:1018) at net.minecraft.client.network.play.ClientPlayNetHandler.func_199525_a(ClientPlayNetHandler.java:1268) at net.minecraft.network.play.server.SUpdateRecipesPacket.func_148833_a(SourceFile:28) at net.minecraft.network.play.server.SUpdateRecipesPacket.func_148833_a(SourceFile:15) at net.minecraft.network.PacketThreadUtil.func_225383_a(SourceFile:21) at net.minecraft.network.PacketThreadUtil$$Lambda$6234/1891947650.run(Unknown Source) at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213166_h(SourceFile:144) at net.minecraft.util.concurrent.RecursiveEventLoop.func_213166_h(SourceFile:23) at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213168_p(SourceFile:118) at net.minecraft.util.concurrent.ThreadTaskExecutor.func_213160_bf(SourceFile:103) at net.minecraft.client.Minecraft.func_195542_b(Minecraft.java:861) at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:384) at net.minecraft.client.main.Main.main(SourceFile:155) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at net.minecraftforge.fml.loading.FMLClientLaunchProvider.lambda$launchService$0(FMLClientLaunchProvider.java:56) at net.minecraftforge.fml.loading.FMLClientLaunchProvider$$Lambda$409/1292325833.call(Unknown Source) at cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37) at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:54) at cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:72) at cpw.mods.modlauncher.Launcher.run(Launcher.java:81) at cpw.mods.modlauncher.Launcher.main(Launcher.java:65)
This repeats for a lot of locations.
Result: empty chests at various locations.

fixed in build I'm releasing now. Please note that 1.14.4 is not ready until MinecraftForge/MinecraftForge#6180 is merged. 1.15.1 already has this system and 1.14.4 should be receiving this shortly.