BUG

WHY DID THIS HAPPEN THE CRASH REPORT IS THIS  IT THINKED I WASON A MULTIPLAYER SERVER BUT I WAS ON A SINGLEPLAYER WORLD

Minecraft Crash Report -------- Minecraft Crash Report ----// My bad.
Time: 1/13/21 4:48 PMDescription: Updating screen events
java.lang.NullPointerException: The validated object is null at org.apache.commons.lang3.Validate.notNull(Validate.java:222) at org.apache.commons.lang3.Validate.notNull(Validate.java:203) at net.minecraft.util.NonNullList.set(SourceFile:45) at net.minecraft.entity.player.InventoryPlayer.func_70299_a(InventoryPlayer.java:513) at net.minecraft.inventory.Slot.func_75215_d(Slot.java:70) at com.mrcrayfish.furniture.gui.containers.ContainerMailBox.func_82846_b(ContainerMailBox.java:88) at net.minecraft.inventory.Container.func_184996_a(Container.java:237) at net.minecraft.client.multiplayer.PlayerControllerMP.func_187098_a(PlayerControllerMP.java:556) at net.minecraft.client.gui.inventory.GuiContainer.func_184098_a(GuiContainer.java:632) at net.minecraft.client.gui.inventory.GuiContainer.func_73864_a(GuiContainer.java:391) at net.minecraft.client.gui.GuiScreen.func_146274_d(GuiScreen.java:544) at net.minecraft.client.gui.GuiScreen.func_146269_k(GuiScreen.java:512) at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1695) at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1056) at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:372) at net.minecraft.client.main.Main.main(SourceFile:124) 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.minecraft.launchwrapper.Launch.launch(Launch.java:135) at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

A detailed walkthrough of the error, its code path and all known details is as follows:---------------------------------------------------------------------------------------
– Head --Thread: Client threadStacktrace: at org.apache.commons.lang3.Validate.notNull(Validate.java:222) at org.apache.commons.lang3.Validate.notNull(Validate.java:203) at net.minecraft.util.NonNullList.set(SourceFile:45) at net.minecraft.entity.player.InventoryPlayer.func_70299_a(InventoryPlayer.java:513) at net.minecraft.inventory.Slot.func_75215_d(Slot.java:70) at com.mrcrayfish.furniture.gui.containers.ContainerMailBox.func_82846_b(ContainerMailBox.java:88) at net.minecraft.inventory.Container.func_184996_a(Container.java:237) at net.minecraft.client.multiplayer.PlayerControllerMP.func_187098_a(PlayerControllerMP.java:556) at net.minecraft.client.gui.inventory.GuiContainer.func_184098_a(GuiContainer.java:632) at net.minecraft.client.gui.inventory.GuiContainer.func_73864_a(GuiContainer.java:391) at net.minecraft.client.gui.GuiScreen.func_146274_d(GuiScreen.java:544) at net.minecraft.client.gui.GuiScreen.func_146269_k(GuiScreen.java:512)
– Affected screen --Details: Screen name: com.mrcrayfish.furniture.gui.GuiMailBox
– Affected level --Details: Level name: MpServer All players: 1 total; [EntityPlayerSP['EthanAucoin76'/336, l='MpServer', x=-565.70, y=64.00, z=-85.33]] Chunk stats: MultiplayerChunkCache: 604, 604 Level seed: 0 Level generator: ID 00 - default, ver 1. Features enabled: false Level generator options:  Level spawn location: World: (-568,68,-90), Chunk: (at 8,4,6 in -36,-6; contains blocks -576,0,-96 to -561,255,-81), Region: (-2,-1; contains chunks -64,-32 to -33,-1, blocks -1024,0,-512 to -513,255,-1) Level time: 116732 game time, 46849 day time Level dimension: 0 Level storage version: 0x00000 - Unknown? Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false) Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false Forced entities: 120 total; [EntityCreeper['Creeper'/66, l='MpServer', x=-641.68, y=81.00, z=-89.67], EntityPig['Pig'/68, l='MpServer', x=-636.50, y=71.23, z=-26.33], EntityBat['Bat'/77, l='MpServer', x=-637.25, y=13.69, z=-154.59], EntityZombie['Zombie'/78, l='MpServer', x=-631.74, y=64.00, z=-141.55], EntityChicken['Chicken'/79, l='MpServer', x=-624.15, y=74.00, z=-72.61], EntityChicken['Chicken'/80, l='MpServer', x=-628.39, y=73.00, z=-76.12], EntityPlayerSP['EthanAucoin76'/336, l='MpServer', x=-565.70, y=64.00, z=-85.33], EntitySheep['Sheep'/81, l='MpServer', x=-628.74, y=74.00, z=-67.99], EntitySkeleton['Skeleton'/82, l='MpServer', x=-630.50, y=42.00, z=-52.50], EntitySkeleton['Skeleton'/83, l='MpServer', x=-629.50, y=42.00, z=-53.50], EntitySheep['Sheep'/84, l='MpServer', x=-627.43, y=74.00, z=-63.23], EntitySheep['Sheep'/85, l='MpServer', x=-630.25, y=74.00, z=-62.22], EntityZombie['Zombie'/86, l='MpServer', x=-631.50, y=38.00, z=-45.50], EntitySkeleton['Skeleton'/91, l='MpServer', x=-616.50, y=63.00, z=-86.50], EntityCreeper['Creeper'/92, l='MpServer', x=-614.80, y=27.00, z=-74.49], EntityChicken['Chicken'/93, l='MpServer', x=-623.52, y=74.00, z=-75.16], EntitySpider['Spider'/94, l='MpServer', x=-631.48, y=74.00, z=-61.12], EntityChicken['Chicken'/95, l='MpServer', x=-621.08, y=74.00, z=-60.08], EntityItem['item.item.egg'/96, l='MpServer', x=-614.77, y=74.00, z=-53.26], EntitySheep['Sheep'/97, l='MpServer', x=-612.27, y=72.00, z=-31.43], EntitySpider['Spider'/98, l='MpServer', x=-608.50, y=70.00, z=-19.50], EntitySpider['Spider'/100, l='MpServer', x=-602.50, y=63.00, z=-153.50], EntitySkeleton['Skeleton'/101, l='MpServer', x=-605.50, y=73.00, z=-95.50], EntityCreeper['Creeper'/102, l='MpServer', x=-602.01, y=20.00, z=-77.55], EntitySheep['Sheep'/103, l='MpServer', x=-601.46, y=69.00, z=-49.55], EntitySheep['Sheep'/104, l='MpServer', x=-604.18, y=73.00, z=-42.28], EntitySheep['Sheep'/105, l='MpServer', x=-605.24, y=72.00, z=-47.55], EntitySpider['Spider'/113, l='MpServer', x=-584.98, y=31.00, z=-137.00], EntityCreeper['Creeper'/114, l='MpServer', x=-584.80, y=61.00, z=-143.48], EntitySheep['Sheep'/115, l='MpServer', x=-588.50, y=72.00, z=-117.82], EntitySpider['Spider'/116, l='MpServer', x=-577.01, y=71.00, z=-125.99], EntitySheep['Sheep'/117, l='MpServer', x=-589.16, y=72.00, z=-34.91], EntitySheep['Sheep'/118, l='MpServer', x=-583.46, y=73.00, z=-37.72], EntitySheep['Sheep'/119, l='MpServer', x=-584.73, y=72.00, z=-35.23], EntitySheep['Sheep'/120, l='MpServer', x=-593.74, y=72.00, z=-37.42], EntityChicken['Chicken'/140, l='MpServer', x=-564.56, y=67.00, z=-147.56], EntityChicken['Chicken'/141, l='MpServer', x=-562.46, y=69.00, z=-150.13], EntityCreeper['Creeper'/143, l='MpServer', x=-575.50, y=30.00, z=-134.50], EntityCreeper['Creeper'/144, l='MpServer', x=-566.50, y=77.00, z=-122.50], EntityCreeper['Creeper'/145, l='MpServer', x=-572.37, y=61.00, z=-101.04], EntitySheep['Sheep'/146, l='MpServer', x=-555.21, y=74.00, z=-38.18], EntitySheep['Sheep'/147, l='MpServer', x=-574.19, y=71.00, z=-27.52], EntitySheep['Sheep'/148, l='MpServer', x=-560.21, y=72.00, z=-28.55], EntitySheep['Sheep'/149, l='MpServer', x=-564.61, y=71.00, z=-25.73], EntityChicken['Chicken'/159, l='MpServer', x=-565.53, y=69.00, z=-150.13], EntityItem['item.item.egg'/160, l='MpServer', x=-558.81, y=67.00, z=-147.55], EntityZombieVillager['Zombie Villager'/161, l='MpServer', x=-550.19, y=69.00, z=-153.30], EntityChicken['Chicken'/162, l='MpServer', x=-567.47, y=73.25, z=-134.97], EntityItem['item.item.egg'/163, l='MpServer', x=-559.06, y=70.00, z=-139.32], EntityCreeper['Creeper'/164, l='MpServer', x=-553.50, y=15.00, z=-112.50], EntitySheep['Sheep'/165, l='MpServer', x=-559.45, y=72.00, z=-127.55], EntitySheep['Sheep'/166, l='MpServer', x=-551.80, y=76.00, z=-117.49], EntitySheep['Sheep'/167, l='MpServer', x=-551.27, y=80.00, z=-128.53], EntityBat['Bat'/168, l='MpServer', x=-558.47, y=61.10, z=-100.75], EntityBat['Bat'/169, l='MpServer', x=-554.50, y=55.10, z=-99.64], EntityBat['Bat'/170, l='MpServer', x=-553.43, y=55.10, z=-99.63], EntityBat['Bat'/171, l='MpServer', x=-553.25, y=55.10, z=-99.75], EntityBat['Bat'/172, l='MpServer', x=-556.36, y=56.10, z=-101.25], EntityBat['Bat'/173, l='MpServer', x=-553.57, y=54.10, z=-98.25], EntityBat['Bat'/174, l='MpServer', x=-558.51, y=60.10, z=-101.75], EntityBat['Bat'/175, l='MpServer', x=-555.25, y=56.10, z=-102.75], EntityBat['Bat'/176, l='MpServer', x=-551.02, y=58.57, z=-101.77], EntityBat['Bat'/177, l='MpServer', x=-549.43, y=59.10, z=-80.25], EntityBat['Bat'/178, l='MpServer', x=-550.34, y=59.10, z=-83.07], EntityCreeper['Creeper'/179, l='MpServer', x=-551.38, y=57.00, z=-80.50], EntityCreeper['Creeper'/180, l='MpServer', x=-553.99, y=64.00, z=-91.82], EntitySkeleton['Skeleton'/181, l='MpServer', x=-556.45, y=59.00, z=-66.78], EntityZombie['Zombie'/182, l='MpServer', x=-542.46, y=24.00, z=-52.79], EntitySheep['Sheep'/183, l='MpServer', x=-544.50, y=72.00, z=-42.55], EntitySheep['Sheep'/184, l='MpServer', x=-552.76, y=74.00, z=-38.55], EntitySheep['Sheep'/185, l='MpServer', x=-559.21, y=71.00, z=-24.54], EntitySheep['Sheep'/189, l='MpServer', x=-526.73, y=79.00, z=-138.51], EntitySkeleton['Skeleton'/190, l='MpServer', x=-533.50, y=26.00, z=-106.50], EntitySkeleton['Skeleton'/191, l='MpServer', x=-529.50, y=29.00, z=-100.50], EntityZombie['Zombie'/192, l='MpServer', x=-541.50, y=29.00, z=-98.50], EntityZombie['Zombie'/193, l='MpServer', x=-533.51, y=67.00, z=-101.19], EntityZombie['Zombie'/194, l='MpServer', x=-540.81, y=30.00, z=-92.50], EntityZombie['Zombie'/195, l='MpServer', x=-537.50, y=29.00, z=-91.50], EntityBat['Bat'/196, l='MpServer', x=-541.73, y=52.10, z=-86.69], EntityZombie['Zombie'/197, l='MpServer', x=-531.61, y=65.00, z=-92.49], EntitySpider['Spider'/198, l='MpServer', x=-530.50, y=67.00, z=-66.50], EntityCreeper['Creeper'/199, l='MpServer', x=-535.50, y=66.00, z=-69.50], EntitySkeleton['Skeleton'/200, l='MpServer', x=-528.50, y=67.00, z=-57.50], EntityCreeper['Creeper'/201, l='MpServer', x=-528.15, y=67.00, z=-54.47], EntitySheep['Sheep'/202, l='MpServer', x=-543.27, y=73.00, z=-44.51], EntitySheep['Sheep'/203, l='MpServer', x=-541.55, y=69.00, z=-40.50], EntitySheep['Sheep'/204, l='MpServer', x=-521.65, y=80.00, z=-152.81], EntityBat['Bat'/205, l='MpServer', x=-508.63, y=32.90, z=-141.01], EntityBat['Bat'/206, l='MpServer', x=-508.00, y=30.86, z=-138.67], EntitySheep['Sheep'/207, l='MpServer', x=-524.50, y=79.00, z=-140.73], EntitySheep['Sheep'/208, l='MpServer', x=-520.51, y=79.00, z=-141.73], EntityCreeper['Creeper'/209, l='MpServer', x=-513.50, y=84.00, z=-134.50], EntityCreeper['Creeper'/210, l='MpServer', x=-517.50, y=85.00, z=-129.50], EntityChicken['Chicken'/211, l='MpServer', x=-522.16, y=69.00, z=-98.30], EntitySheep['Sheep'/212, l='MpServer', x=-521.74, y=67.00, z=-83.23], EntityChicken['Chicken'/213, l='MpServer', x=-513.86, y=68.00, z=-89.56], EntityItem['item.item.egg'/214, l='MpServer', x=-512.97, y=68.00, z=-89.10], EntityItem['item.item.egg'/215, l='MpServer', x=-514.97, y=69.00, z=-95.56], EntityChicken['Chicken'/216, l='MpServer', x=-524.49, y=67.00, z=-65.88], EntitySheep['Sheep'/217, l='MpServer', x=-527.75, y=66.00, z=-77.07], EntityCreeper['Creeper'/218, l='MpServer', x=-520.80, y=67.00, z=-76.13], EntityChicken['Chicken'/219, l='MpServer', x=-520.52, y=68.00, z=-61.87], EntityItem['item.item.egg'/220, l='MpServer', x=-520.41, y=68.00, z=-62.02], EntitySheep['Sheep'/221, l='MpServer', x=-516.56, y=67.00, z=-33.76], EntitySheep['Sheep'/222, l='MpServer', x=-519.92, y=67.00, z=-33.80], EntitySheep['Sheep'/223, l='MpServer', x=-527.55, y=67.00, z=-19.45], EntitySheep['Sheep'/226, l='MpServer', x=-505.49, y=88.00, z=-155.78], EntitySheep['Sheep'/227, l='MpServer', x=-502.53, y=85.00, z=-143.18], EntitySheep['Sheep'/228, l='MpServer', x=-501.16, y=85.00, z=-143.57], EntityZombieVillager['Zombie Villager'/229, l='MpServer', x=-500.59, y=43.00, z=-116.23], EntitySheep['Sheep'/230, l='MpServer', x=-505.27, y=72.00, z=-105.48], EntityCreeper['Creeper'/231, l='MpServer', x=-510.18, y=67.00, z=-101.49], EntitySheep['Sheep'/232, l='MpServer', x=-511.33, y=67.00, z=-81.32], EntitySheep['Sheep'/233, l='MpServer', x=-502.51, y=68.00, z=-87.24], EntitySheep['Sheep'/234, l='MpServer', x=-509.25, y=67.00, z=-78.44], EntityZombie['Zombie'/235, l='MpServer', x=-507.50, y=68.00, z=-11.50], EntitySheep['Sheep'/241, l='MpServer', x=-495.51, y=86.00, z=-149.27], EntitySheep['Sheep'/242, l='MpServer', x=-487.78, y=69.00, z=-88.58], EntitySheep['Sheep'/243, l='MpServer', x=-503.20, y=68.00, z=-75.28], EntitySkeleton['Skeleton'/244, l='MpServer', x=-491.50, y=60.00, z=-57.50]] Retry entities: 0 total; [] Server brand: fml,forge Server type: Integrated singleplayer serverStacktrace: at net.minecraft.client.multiplayer.WorldClient.func_72914_a(WorldClient.java:415) at net.minecraft.client.Minecraft.func_71396_d(Minecraft.java:2655) at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:393) at net.minecraft.client.main.Main.main(SourceFile:124) 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.minecraft.launchwrapper.Launch.launch(Launch.java:135) at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
– System Details --Details: Minecraft Version: 1.11.2 Operating System: Windows 10 (amd64) version 10.0 Java Version: 1.8.0_51, Oracle Corporation Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation Memory: 497499640 bytes (474 MB) / 1073741824 bytes (1024 MB) up to 2147483648 bytes (2048 MB) JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95 FML: MCP 9.38 Powered by Forge 13.20.1.2588 6 mods loaded, 6 mods active States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored UCHIJAAAA minecraft{1.11.2} [Minecraft] (minecraft.jar)  UCHIJAAAA mcp{9.19} [Minecraft Coder Pack] (minecraft.jar)  UCHIJAAAA FML{8.0.99.99} [Forge Mod Loader] (forge-1.11.2-13.20.1.2588.jar)  UCHIJAAAA forge{13.20.1.2588} [Minecraft Forge] (forge-1.11.2-13.20.1.2588.jar)  UCHIJAAAA mercurius_updater{1.0} [mercurius_updater] (MercuriusUpdater-1.11.2.jar)  UCHIJAAAA cfm{4.1} [MrCrayfish's Furniture Mod] (cfm-4.1-mc1.11.2.jar)  Loaded coremods (and transformers):  GL info: ' Vendor: 'Intel' Version: '4.6.0 - Build 27.20.100.8729' Renderer: 'Intel(R) Iris(R) Xe Graphics' Launched Version: 1.11.2-forge1.11.2-13.20.1.2588 LWJGL: 2.9.4 OpenGL: Intel(R) Iris(R) Xe Graphics GL version 4.6.0 - Build 27.20.100.8729, Intel GL Caps: Using GL 1.3 multitexturing.Using GL 1.3 texture combiners.Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.Shaders are available because OpenGL 2.1 is supported.VBOs are available because OpenGL 1.5 is supported.
Using VBOs: Yes Is Modded: Definitely; Client brand changed to 'fml,forge' Type: Client (map_client.txt) Resource Packs:  Current Language: English (US) Profiler Position: N/A (disabled) CPU: 8x 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz