[1.8] ItemStack of Dark Oak Door has null delegate

[FreshmanTV]

So, im working at a kind of Guide Book. A created a kind of abstraction for it, one of them is the class "CraftingRecipe". When you call the draw method of this class, it should draw a crafting grid(works) and the items/blocks that are located in the grid. I copied the method "drawItemStack" from GuiContainer to draw the itemsstacks:

public void drawItemStack(ItemStack stack, int x, int y, String altText) {
        RenderHelper.disableStandardItemLighting();
        RenderHelper.enableGUIStandardItemLighting();
        GlStateManager.translate(0.0F, 0.0F, 32.0F);
        zLevel = 200.0F;
        itemRender.zLevel = 200.0F;
        FontRenderer font = null;
        if (stack != null && stack.getItem() != null) {
            font = stack.getItem().getFontRenderer(stack);
            if (font == null)
                font = fontRendererObj;
            itemRender.renderItemAndEffectIntoGUI(stack, x, y);
            itemRender.renderItemOverlayIntoGUI(font, stack, x, y, altText);
        }
        zLevel = 0.0F;
        itemRender.zLevel = 0.0F;
        RenderHelper.enableStandardItemLighting();
    }

This method also works fine, but not for the dark oak door. Here is the log:
 

Spoiler

net.minecraft.util.ReportedException: Rendering screen
    at net.minecraft.client.renderer.EntityRenderer.updateCameraAndRender(EntityRenderer.java:1167) ~[EntityRenderer.class:?]
    at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1114) ~[Minecraft.class:?]
    at net.minecraft.client.Minecraft.run(Minecraft.java:376) [Minecraft.class:?]
    at net.minecraft.client.main.Main.main(Main.java:117) [Main.class:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_211]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_211]
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) [launchwrapper-1.12.jar:?]
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_211]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_211]
    at net.minecraftforge.gradle.GradleStartCommon.launch(Unknown Source) [start/:?]
    at GradleStart.main(Unknown Source) [start/:?]
Caused by: java.lang.NullPointerException
    at de.freshmantv.ttm.gui.guide_book.GuiGuideBook.drawItemStack(GuiGuideBook.java:152) ~[GuiGuideBook.class:?]
    at de.freshmantv.ttm.gui.guide_book.CraftingRecipe.draw(CraftingRecipe.java:42) ~[CraftingRecipe.class:?]
    at de.freshmantv.ttm.gui.guide_book.GuiGuideBook.drawScreen(GuiGuideBook.java:123) ~[GuiGuideBook.class:?]
    at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:470) ~[ForgeHooksClient.class:?]
    at net.minecraft.client.renderer.EntityRenderer.updateCameraAndRender(EntityRenderer.java:1137) ~[EntityRenderer.class:?]
    ... 15 more
[18:01:36] [Client thread/INFO] [STDOUT]: [net.minecraft.init.Bootstrap:printToSYSOUT:663]: ---- Minecraft Crash Report ----
// My bad.

Time: 17.05.19 18:01
Description: Rendering screen

java.lang.NullPointerException: Rendering screen
    at de.freshmantv.ttm.gui.guide_book.GuiGuideBook.drawItemStack(GuiGuideBook.java:152)
    at de.freshmantv.ttm.gui.guide_book.CraftingRecipe.draw(CraftingRecipe.java:42)
    at de.freshmantv.ttm.gui.guide_book.GuiGuideBook.drawScreen(GuiGuideBook.java:123)
    at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:470)
    at net.minecraft.client.renderer.EntityRenderer.updateCameraAndRender(EntityRenderer.java:1137)
    at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1114)
    at net.minecraft.client.Minecraft.run(Minecraft.java:376)
    at net.minecraft.client.main.Main.main(Main.java:117)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at net.minecraftforge.gradle.GradleStartCommon.launch(Unknown Source)
    at GradleStart.main(Unknown Source)

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

-- Head --
Stacktrace:
    at de.freshmantv.ttm.gui.guide_book.GuiGuideBook.drawItemStack(GuiGuideBook.java:152)
    at de.freshmantv.ttm.gui.guide_book.CraftingRecipe.draw(CraftingRecipe.java:42)
    at de.freshmantv.ttm.gui.guide_book.GuiGuideBook.drawScreen(GuiGuideBook.java:123)
    at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:470)

-- Screen render details --
Details:
    Screen name: de.freshmantv.ttm.gui.guide_book.GuiGuideBook
    Mouse location: Scaled: (228, 127). Absolute: (683, 384)
    Screen size: Scaled: (456, 256). Absolute: (1366, 768). Scale factor of 3

-- Affected level --
Details:
    Level name: MpServer
    All players: 1 total; [EntityPlayerSP['Player245'/333, l='MpServer', x=-39,91, y=65,00, z=244,97]]
    Chunk stats: MultiplayerChunkCache: 289, 289
    Level seed: 0
    Level generator: ID 00 - default, ver 1. Features enabled: false
    Level generator options: 
    Level spawn location: -32,00,64,00,256,00 - World: (-32,64,256), Chunk: (at 0,4,0 in -2,16; contains blocks -32,0,256 to -17,255,271), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
    Level time: 27604 game time, 3065 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: 121 total; [EntityPig['Pig'/256, l='MpServer', x=39,00, y=63,00, z=309,88], EntityCreeper['Creeper'/66, l='MpServer', x=-116,59, y=26,00, z=195,06], EntityZombie['Zombie'/67, l='MpServer', x=-117,09, y=32,00, z=223,53], EntityRabbit['Rabbit'/68, l='MpServer', x=-115,38, y=68,00, z=256,78], EntityRabbit['Rabbit'/69, l='MpServer', x=-117,72, y=68,00, z=264,38], EntityZombie['Zombie'/71, l='MpServer', x=-112,56, y=20,00, z=304,03], EntityPlayerSP['Player245'/333, l='MpServer', x=-39,91, y=65,00, z=244,97], EntityPig['Pig'/78, l='MpServer', x=-105,84, y=67,00, z=170,44], EntityZombie['Zombie'/79, l='MpServer', x=-103,47, y=13,00, z=200,06], EntityCreeper['Creeper'/80, l='MpServer', x=-110,03, y=44,00, z=198,41], EntitySkeleton['Skeleton'/81, l='MpServer', x=-101,34, y=48,00, z=208,28], EntityRabbit['Rabbit'/82, l='MpServer', x=-109,84, y=65,28, z=234,72], EntityPig['Pig'/83, l='MpServer', x=-97,88, y=69,00, z=259,53], EntitySkeleton['Skeleton'/84, l='MpServer', x=-101,78, y=20,00, z=301,84], EntityBat['Bat'/85, l='MpServer', x=-100,75, y=43,10, z=314,25], EntityPig['Pig'/91, l='MpServer', x=-81,47, y=70,00, z=171,97], EntityPig['Pig'/92, l='MpServer', x=-92,47, y=64,00, z=183,50], EntityPig['Pig'/93, l='MpServer', x=-81,81, y=64,00, z=181,47], EntityWitch['Witch'/94, l='MpServer', x=-83,81, y=41,63, z=205,63], EntityZombie['Zombie'/95, l='MpServer', x=-87,22, y=35,00, z=232,84], EntityWitch['Witch'/96, l='MpServer', x=-84,31, y=48,00, z=226,63], EntityPig['Pig'/97, l='MpServer', x=-85,81, y=68,00, z=224,44], EntityBat['Bat'/98, l='MpServer', x=-95,59, y=21,10, z=246,56], EntityBat['Bat'/99, l='MpServer', x=-85,50, y=36,10, z=244,44], EntityPig['Pig'/100, l='MpServer', x=-81,00, y=72,00, z=252,00], EntitySpider['Spider'/101, l='MpServer', x=-81,34, y=16,00, z=273,69], EntitySkeleton['Skeleton'/102, l='MpServer', x=-81,41, y=13,00, z=295,19], EntitySkeleton['Skeleton'/103, l='MpServer', x=-80,56, y=13,00, z=299,09], EntityPig['Pig'/112, l='MpServer', x=-76,28, y=67,00, z=167,53], EntityPig['Pig'/113, l='MpServer', x=-75,56, y=64,00, z=169,94], EntitySkeleton['Skeleton'/114, l='MpServer', x=-76,94, y=27,00, z=240,69], EntityBat['Bat'/115, l='MpServer', x=-70,72, y=36,10, z=252,59], EntityZombie['Zombie'/116, l='MpServer', x=-76,06, y=11,00, z=268,66], EntityBat['Bat'/117, l='MpServer', x=-69,50, y=37,10, z=258,25], EntityBat['Bat'/118, l='MpServer', x=-78,06, y=43,10, z=260,31], EntityZombie['Zombie'/119, l='MpServer', x=-78,50, y=41,00, z=279,22], EntitySheep['Sheep'/120, l='MpServer', x=-75,09, y=72,00, z=274,84], EntityPig['Pig'/121, l='MpServer', x=-79,56, y=74,00, z=286,00], EntitySheep['Sheep'/122, l='MpServer', x=-75,97, y=72,00, z=278,78], EntityPig['Pig'/127, l='MpServer', x=-53,28, y=64,00, z=217,72], EntityPig['Pig'/128, l='MpServer', x=-56,50, y=65,00, z=219,63], EntityCreeper['Creeper'/129, l='MpServer', x=-63,81, y=10,00, z=264,84], EntityCreeper['Creeper'/130, l='MpServer', x=-62,31, y=31,00, z=288,63], EntityPig['Pig'/131, l='MpServer', x=-53,41, y=68,00, z=299,03], EntitySpider['Spider'/132, l='MpServer', x=-55,31, y=32,42, z=309,53], EntityPig['Pig'/133, l='MpServer', x=-52,53, y=68,00, z=308,28], EntityPig['Pig'/134, l='MpServer', x=-64,00, y=67,00, z=313,97], EntityZombie['Zombie'/144, l='MpServer', x=-40,41, y=50,00, z=193,03], EntitySkeleton['Skeleton'/145, l='MpServer', x=-41,47, y=53,00, z=198,84], EntitySkeleton['Skeleton'/146, l='MpServer', x=-39,16, y=24,00, z=259,25], EntitySkeleton['Skeleton'/147, l='MpServer', x=-40,50, y=22,00, z=260,84], EntitySkeleton['Skeleton'/148, l='MpServer', x=-37,75, y=40,00, z=265,84], EntityCreeper['Creeper'/149, l='MpServer', x=-40,72, y=15,00, z=275,38], EntitySkeleton['Skeleton'/150, l='MpServer', x=-39,34, y=15,00, z=274,31], EntitySheep['Sheep'/151, l='MpServer', x=-41,91, y=64,00, z=284,91], EntityCreeper['Creeper'/152, l='MpServer', x=-45,78, y=45,00, z=297,47], EntityCreeper['Creeper'/153, l='MpServer', x=-38,09, y=45,00, z=308,91], EntityPig['Pig'/158, l='MpServer', x=-16,69, y=69,00, z=169,38], EntityZombie['Zombie'/159, l='MpServer', x=-17,09, y=56,00, z=188,59], EntitySkeleton['Skeleton'/160, l='MpServer', x=-17,22, y=37,00, z=192,53], EntityZombie['Zombie'/161, l='MpServer', x=-23,31, y=44,00, z=191,81], EntitySkeleton['Skeleton'/162, l='MpServer', x=-19,25, y=45,00, z=203,13], EntityZombie['Zombie'/163, l='MpServer', x=-28,72, y=19,06, z=213,69], EntityCreeper['Creeper'/164, l='MpServer', x=-19,50, y=25,00, z=222,31], EntityZombie['Zombie'/165, l='MpServer', x=-23,13, y=25,00, z=223,44], EntityBat['Bat'/166, l='MpServer', x=-19,38, y=27,10, z=212,63], EntitySheep['Sheep'/167, l='MpServer', x=-20,53, y=63,00, z=221,47], EntityPig['Pig'/168, l='MpServer', x=-18,78, y=68,00, z=208,53], EntityCreeper['Creeper'/169, l='MpServer', x=-24,22, y=14,00, z=237,44], EntityCreeper['Creeper'/170, l='MpServer', x=-23,44, y=24,00, z=236,63], EntityPig['Pig'/171, l='MpServer', x=-20,94, y=62,00, z=224,03], EntityBat['Bat'/172, l='MpServer', x=-29,25, y=24,10, z=254,28], EntityBat['Bat'/173, l='MpServer', x=-25,63, y=23,10, z=248,75], EntityPig['Pig'/174, l='MpServer', x=-24,38, y=63,00, z=271,28], EntitySheep['Sheep'/175, l='MpServer', x=-21,81, y=63,00, z=280,38], EntityPig['Pig'/176, l='MpServer', x=-31,75, y=64,00, z=289,03], EntityBat['Bat'/177, l='MpServer', x=-29,25, y=39,10, z=304,53], EntityZombie['Zombie'/178, l='MpServer', x=-21,50, y=50,00, z=319,06], EntitySheep['Sheep'/182, l='MpServer', x=-9,47, y=71,00, z=167,41], EntityCreeper['Creeper'/183, l='MpServer', x=-11,69, y=23,00, z=189,88], EntitySkeleton['Skeleton'/184, l='MpServer', x=-14,91, y=47,00, z=189,50], EntityPig['Pig'/185, l='MpServer', x=-5,94, y=72,00, z=177,03], EntityZombie['Zombie'/186, l='MpServer', x=-6,06, y=31,00, z=195,50], EntityZombie['Zombie'/187, l='MpServer', x=-11,16, y=28,00, z=203,59], EntitySkeleton['Skeleton'/188, l='MpServer', x=-7,06, y=37,00, z=205,38], EntityCreeper['Creeper'/189, l='MpServer', x=-5,41, y=35,00, z=204,00], EntityBat['Bat'/190, l='MpServer', x=-4,25, y=32,10, z=198,75], EntityBat['Bat'/191, l='MpServer', x=-7,25, y=54,10, z=204,69], EntityPig['Pig'/192, l='MpServer', x=-10,56, y=68,00, z=216,44], EntitySheep['Sheep'/193, l='MpServer', x=-12,56, y=68,00, z=217,63], EntityPig['Pig'/194, l='MpServer', x=-13,78, y=68,00, z=217,34], EntityPig['Pig'/195, l='MpServer', x=-8,59, y=66,00, z=217,50], EntityPig['Pig'/196, l='MpServer', x=-13,53, y=63,00, z=226,50], EntityCreeper['Creeper'/197, l='MpServer', x=-8,41, y=11,00, z=248,00], EntityBat['Bat'/198, l='MpServer', x=-0,50, y=30,10, z=258,59], EntityBat['Bat'/199, l='MpServer', x=-11,25, y=40,10, z=294,75], EntityPig['Pig'/200, l='MpServer', x=-0,31, y=65,00, z=293,44], EntityPig['Pig'/201, l='MpServer', x=-11,22, y=64,00, z=316,53], EntityPig['Pig'/202, l='MpServer', x=-12,44, y=64,00, z=310,81], EntityPig['Pig'/210, l='MpServer', x=7,44, y=64,02, z=165,06], EntitySkeleton['Skeleton'/211, l='MpServer', x=-4,47, y=38,00, z=197,31], EntityPig['Pig'/212, l='MpServer', x=1,44, y=68,00, z=186,53], EntityPig['Pig'/213, l='MpServer', x=3,97, y=69,00, z=182,34], EntityPig['Pig'/214, l='MpServer', x=2,72, y=70,00, z=180,00], EntityCreeper['Creeper'/215, l='MpServer', x=6,00, y=22,00, z=206,41], EntityCreeper['Creeper'/216, l='MpServer', x=2,59, y=46,00, z=202,97], EntitySkeleton['Skeleton'/217, l='MpServer', x=5,97, y=47,00, z=207,66], EntitySpider['Spider'/218, l='MpServer', x=13,28, y=46,00, z=205,72], EntitySkeleton['Skeleton'/219, l='MpServer', x=3,06, y=57,00, z=192,41], EntitySkeleton['Skeleton'/220, l='MpServer', x=9,88, y=39,00, z=247,47], EntityBat['Bat'/221, l='MpServer', x=0,28, y=41,10, z=287,16], EntitySpider['Spider'/222, l='MpServer', x=0,69, y=45,59, z=313,38], EntitySheep['Sheep'/241, l='MpServer', x=17,06, y=63,00, z=185,09], EntityZombie['Zombie'/242, l='MpServer', x=25,00, y=13,00, z=199,94], EntitySkeleton['Skeleton'/243, l='MpServer', x=20,41, y=13,00, z=197,91], EntityCreeper['Creeper'/244, l='MpServer', x=17,03, y=11,00, z=196,41], EntityPig['Pig'/245, l='MpServer', x=13,94, y=64,00, z=224,94], EntitySkeleton['Skeleton'/246, l='MpServer', x=17,50, y=23,00, z=248,09], EntityPig['Pig'/247, l='MpServer', x=38,63, y=63,00, z=306,28], EntityPig['Pig'/252, l='MpServer', x=32,78, y=63,00, z=209,66], EntityBat['Bat'/255, l='MpServer', x=35,44, y=36,10, z=279,44]]
    Retry entities: 0 total; []
    Server brand: fml,forge
    Server type: Integrated singleplayer server
Stacktrace:
    at net.minecraft.client.multiplayer.WorldClient.addWorldInfoToCrashReport(WorldClient.java:392)
    at net.minecraft.client.Minecraft.addGraphicsAndWorldToCrashReport(Minecraft.java:2614)
    at net.minecraft.client.Minecraft.run(Minecraft.java:398)
    at net.minecraft.client.main.Main.main(Main.java:117)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at net.minecraftforge.gradle.GradleStartCommon.launch(Unknown Source)
    at GradleStart.main(Unknown Source)

-- System Details --
Details:
    Minecraft Version: 1.8
    Operating System: Windows 10 (amd64) version 10.0
    Java Version: 1.8.0_211, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 650053856 bytes (619 MB) / 1038876672 bytes (990 MB) up to 1038876672 bytes (990 MB)
    JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M
    IntCache: cache: 1, tcache: 0, allocated: 13, tallocated: 95
    FML: MCP v9.10 FML v8.0.99.99 Minecraft Forge 11.14.4.1577 4 mods loaded, 4 mods active
    States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
    UCHIJAAAA    mcp{9.05} [Minecraft Coder Pack] (minecraft.jar) 
    UCHIJAAAA    FML{8.0.99.99} [Forge Mod Loader] (forgeSrc-1.8-11.14.4.1577.jar) 
    UCHIJAAAA    Forge{11.14.4.1577} [Minecraft Forge] (forgeSrc-1.8-11.14.4.1577.jar) 
    UCHIJAAAA    ttm{0.1-BETA} [ttm] (bin) 
    Loaded coremods (and transformers): 
    GL info: ' Vendor: 'NVIDIA Corporation' Version: '4.6.0 NVIDIA 430.64' Renderer: 'GeForce 930M/PCIe/SSE2'
    Launched Version: 1.8
    LWJGL: 2.9.1
    OpenGL: GeForce 930M/PCIe/SSE2 GL version 4.6.0 NVIDIA 430.64, NVIDIA Corporation
    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)
[18:01:36] [Client thread/INFO] [STDOUT]: [net.minecraft.init.Bootstrap:printToSYSOUT:663]: #@!@# Game crashed! Crash report saved to: #@!@# C:\Users\rojer\Entwicklung\Projekte\Java Projekte\Programs\Games\Minecraft Mods\TTM\TimeTravelMod\run\.\crash-reports\crash-2019-05-17_18.01.36-client.txt
AL lib: (EE) alc_cleanup: 1 device not closed
Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
 

Why does this error happen and how can I fix it?