I am in multiplayer with a friend of mine, and he didn't crash.
Here's my crash report:
---- Minecraft Crash Report ----

WARNING: coremods are present:
ThaumcraftLoader (Thaumcraft-1.8.9-5.1.6.jar)
FldLoadingPlugin (FastLeafDecay-1.8-1.6.jar)
FMLPlugin (InventoryTweaks-1.60-beta-30.jar)
TrashSlot (trashslot-mc1.8.9-2.0.7.jar)
Contact their authors BEFORE contacting forge

// Would you like a cupcake?

Time: 2/11/16 7:29 PM
Description: Rendering screen

java.lang.NullPointerException: Rendering screen
at vazkii.psi.client.gui.GuiProgrammer.func_73863_a(GuiProgrammer.java:234)
at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:309)
at net.minecraft.client.renderer.EntityRenderer.func_181560_a(EntityRenderer.java:1103)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1051)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:349)
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:483)
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 --
Stacktrace:
at vazkii.psi.client.gui.GuiProgrammer.func_73863_a(GuiProgrammer.java:234)
at net.minecraftforge.client.ForgeHooksClient.drawScreen(ForgeHooksClient.java:309)

-- Screen render details --
Details:
Screen name: vazkii.psi.client.gui.GuiProgrammer
Mouse location: Scaled: (377, 179). Absolute: (755, 602)
Screen size: Scaled: (640, 481). Absolute: (1280, 961). Scale factor of 2

-- Affected level --
Details:
Level name: MpServer
All players: 2 total; [EntityPlayerSP['kd8lvt'/3946616, l='MpServer', x=565.43, y=53.00, z=-112.09], EntityOtherPlayerMP['Funniray'/5210067, l='MpServer', x=566.41, y=53.00, z=-110.16]]
Chunk stats: MultiplayerChunkCache: 441, 441
Level seed: 0
Level generator: ID 01 - flat, ver 0. Features enabled: false
Level generator options:
Level spawn location: 527.00,4.00,-165.00 - World: (527,4,-165), Chunk: (at 15,0,11 in 32,-11; contains blocks 512,0,-176 to 527,255,-161), Region: (1,-1; contains chunks 32,-32 to 63,-1, blocks 512,0,-512 to 1023,255,-1)
Level time: 196601 game time, 196601 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: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 33 total; [EntityBat['Bat'/5893459, l='MpServer', x=596.83, y=14.30, z=-130.82], EntityBat['Bat'/5893461, l='MpServer', x=597.25, y=14.40, z=-124.19], EntityBat['Bat'/5893460, l='MpServer', x=597.74, y=14.09, z=-127.89], EntityBat['Bat'/5891650, l='MpServer', x=641.58, y=32.17, z=-172.27], EntityBat['Bat'/5908340, l='MpServer', x=584.25, y=29.10, z=-180.41], EntityBat['Bat'/5913114, l='MpServer', x=624.11, y=21.00, z=-39.07], EntityBat['Bat'/5913112, l='MpServer', x=627.13, y=21.56, z=-41.54], EntityBat['Bat'/5913099, l='MpServer', x=643.75, y=21.99, z=-44.31], EntityAuraNode['Aura Node'/96, l='MpServer', x=507.50, y=74.50, z=-177.50], EntityBat['Bat'/5831998, l='MpServer', x=600.59, y=3.29, z=-90.22], EntityAuraNode['Aura Node'/113, l='MpServer', x=535.50, y=64.50, z=-165.50], EntityAuraNode['Aura Node'/114, l='MpServer', x=543.50, y=70.50, z=-116.50], EntityAuraNode['Aura Node'/115, l='MpServer', x=513.50, y=78.50, z=-68.50], EntitySquid['Squid'/5526318, l='MpServer', x=557.96, y=46.72, z=-97.10], EntitySquid['Squid'/5526319, l='MpServer', x=562.51, y=46.00, z=-97.78], EntityAuraNode['Aura Node'/127, l='MpServer', x=572.50, y=65.50, z=-82.50], EntityBat['Bat'/5891551, l='MpServer', x=633.93, y=25.35, z=-130.15], EntityMinecartChest['container.minecart'/140, l='MpServer', x=619.50, y=31.06, z=-171.50], EntityAuraNode['Aura Node'/145, l='MpServer', x=620.50, y=71.50, z=-52.50], EntityOtherPlayerMP['Funniray'/5210067, l='MpServer', x=566.41, y=53.00, z=-110.16], EntityBat['Bat'/5649142, l='MpServer', x=587.52, y=47.95, z=-99.00], EntityBat['Bat'/5819120, l='MpServer', x=591.13, y=28.10, z=-178.50], EntityPlayerSP['kd8lvt'/3946616, l='MpServer', x=565.43, y=53.00, z=-112.09], EntityAuraNode['Aura Node'/293043, l='MpServer', x=433.50, y=86.50, z=14.50], EntityBat['Bat'/5880720, l='MpServer', x=622.26, y=18.01, z=-39.59], EntityBat['Bat'/5880725, l='MpServer', x=625.51, y=17.65, z=-36.52], EntityBat['Bat'/5880714, l='MpServer', x=620.91, y=22.10, z=-47.38], EntityOtherPlayerMP['Funniray'/5210067, l='MpServer', x=566.41, y=53.00, z=-110.16], EntityBat['Bat'/5889157, l='MpServer', x=603.13, y=31.10, z=-180.50], EntitySquid['Squid'/5872056, l='MpServer', x=581.63, y=53.41, z=-68.50], EntityOtherPlayerMP['Funniray'/2223126, l='MpServer', x=594.41, y=2.00, z=-94.81], EntityBat['Bat'/5889185, l='MpServer', x=563.13, y=30.10, z=-172.51], EntityOtherPlayerMP['Funniray'/4568799, l='MpServer', x=566.69, y=53.00, z=-110.97]]
Retry entities: 0 total; []
Server brand: fml,forge
Server type: Non-integrated multiplayer server
Stacktrace:
at net.minecraft.client.multiplayer.WorldClient.func_72914_a(WorldClient.java:347)
at net.minecraft.client.Minecraft.func_71396_d(Minecraft.java:2536)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:370)
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:483)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.8.9
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 1669166832 bytes (1591 MB) / 2606759936 bytes (2486 MB) up to 4772593664 bytes (4551 MB)
JVM Flags: 4 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx5120m -Xms256m -XX:PermSize=256m
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP 9.19 Powered by Forge 11.15.1.1739 32 mods loaded, 32 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
UCHIJA mcp{9.19} Minecraft Coder Pack
UCHIJA FML{8.0.99.99} Forge Mod Loader
UCHIJA Forge{11.15.1.1739} Minecraft Forge
UCHIJA betterbuilderswands{0.4.3} Better Builder's Wands
UCHIJA BloodMagic{1.8.9-2.0.0-16} Blood Magic: Alchemical Wizardry
UCHIJA chancecubes{@Version@} Chance Cubes
UCHIJA ComputerCraft{1.78} ComputerCraft
UCHIJA craftingcraft{2.0.11} CraftingCraft
UCHIJA ezstorage{1.0} EZ Storage
UCHIJA fastleafdecay{1.6} Fast Leaf Decay
UCHIJA furnus{1.7} Furnus
UCHIJA graves{1.8.9-b38-universal} Graves Mod
UCHIJA Baubles{1.1.3.0} Baubles
UCHIJA intangible{0.0.21} Intangible
UCHIJA inventorysorter{0.7.4+26} Simple Inventory sorting
UCHIJA inventorytweaks{1.60-beta-30-48a432c} Inventory Tweaks
UCHIJA IronChest{6.0.125.770} Iron Chest
UCHIJA JEI{2.25.11.150} Just Enough Items
UCHIJA Thaumcraft{5.1.6} Thaumcraft
UCHIJA JEIAddons{0.11.2.56} Just Enough Items Addons
UCHIJA journeymap{5.1.3} JourneyMap
UCHIJA jeresources{0.3.1} Just Enough Resources
UCHIJA mantle{1.8.9-0.7.jenkins72} Mantle
UCHIJA progressiveautomation{1.6.34} Progressive Automation
UCHIJA Psi{beta-11} Psi
UCHIJA psiproducts{1.0.0} Psi Dot Products
UCHIJA RecipeTooltips{1.1.24} RecipeTooltips
UCHIJA tconstruct{1.8.9-2.0.2.jenkins61} Tinkers' Construct
UCHIJA shibeid{1.0.0} [Thaumic Potatoes](Thaumic Potatoes-1.8.9-1.0.1.jar)
UCHIJA trashslot{2.0.7} TrashSlot
UCHIJA VeinMiner{0.31.2_build.unknown} Vein Miner
UCHIJA VeinMinerModSupport{0.31.2_build.unknown} Mod Support
Loaded coremods (and transformers):
ThaumcraftLoader (Thaumcraft-1.8.9-5.1.6.jar)

FldLoadingPlugin (FastLeafDecay-1.8-1.6.jar)
com.olafski.fastleafdecay.FldTransformer
FMLPlugin (InventoryTweaks-1.60-beta-30.jar)
invtweaks.forge.asm.ContainerTransformer
TrashSlot (trashslot-mc1.8.9-2.0.7.jar)
net.blay09.mods.trashslot.coremod.GuiContainerClassTransformer
net.blay09.mods.trashslot.coremod.MinecraftClassTransformer
net.blay09.mods.trashslot.coremod.InventoryTweaksClassTransformer
GL info: ' Vendor: 'ATI Technologies Inc.' Version: '4.5.13401 Compatibility Profile Context 15.201.1301.0' Renderer: 'AMD Radeon HD 7520G'
Pulsar/tconstruct loaded Pulses:
- TinkerCommons (Enabled/Forced)
- TinkerWorld (Enabled/Not Forced)
- TinkerTools (Enabled/Not Forced)
- TinkerSmeltery (Enabled/Not Forced)
- TinkerGadgets (Enabled/Not Forced)
- TinkerOredict (Enabled/Forced)
- TinkerIntegration (Enabled/Forced)
- TinkerFluids (Enabled/Forced)
- TinkerMaterials (Enabled/Forced)
- TinkerDebug (Enabled/Not Forced)

Launched Version: forge-11.15.1.1739
LWJGL: 2.9.4
OpenGL: AMD Radeon HD 7520G GL version 4.5.13401 Compatibility Profile Context 15.201.1301.0, ATI Technologies Inc.
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: No
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: 2x AMD A6-4400M APU with Radeon(tm) HD Graphics