I let the game load up completely. Every time I right clicked anything the game would immediately crash. Tried it with and without Xaeros map mods, but it would still crash every time.

Here's the crash report:

---- Minecraft Crash Report ----
// Don't be sad, have a hug! <3

Time: 6.9.2016 18:02
Description: Unexpected error

java.lang.NoClassDefFoundError: com/pixelmonmod/pixelmon/items/ItemBlock
at com.waterdude.gameshark.event.ClientEventHandler.onBlockRightClicked(ClientEventHandler.java:199)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_60_ClientEventHandler_onBlockRightClicked_PlayerInteractEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:72)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:168)
at net.minecraftforge.common.ForgeHooks.onRightClickBlock(ForgeHooks.java:1001)
at net.minecraft.client.multiplayer.PlayerControllerMP.func_187099_a(PlayerControllerMP.java:387)
at net.minecraft.client.Minecraft.func_147121_ag(Minecraft.java:1518)
at net.minecraft.client.Minecraft.func_184117_aA(Minecraft.java:2184)
at net.minecraft.client.Minecraft.func_184118_az(Minecraft.java:1961)
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1749)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1055)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:371)
at net.minecraft.client.main.Main.main(SourceFile:124)
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)
Caused by: java.lang.ClassNotFoundException: com.pixelmonmod.pixelmon.items.ItemBlock
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 19 more
Caused by: java.lang.NullPointerException


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

-- Head --
Thread: Client thread
Stacktrace:
at com.waterdude.gameshark.event.ClientEventHandler.onBlockRightClicked(ClientEventHandler.java:199)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_60_ClientEventHandler_onBlockRightClicked_PlayerInteractEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:72)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:168)
at net.minecraftforge.common.ForgeHooks.onRightClickBlock(ForgeHooks.java:1001)
at net.minecraft.client.multiplayer.PlayerControllerMP.func_187099_a(PlayerControllerMP.java:387)
at net.minecraft.client.Minecraft.func_147121_ag(Minecraft.java:1518)
at net.minecraft.client.Minecraft.func_184117_aA(Minecraft.java:2184)
at net.minecraft.client.Minecraft.func_184118_az(Minecraft.java:1961)

-- Affected level --
Details:
Level name: MpServer
All players: 1 total; [EntityPlayerSP['MaximusLi'/35, l='MpServer', x=-519,42, y=64,00, z=351,90]]
Chunk stats: MultiplayerChunkCache: 441, 441
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (289,64,12), Chunk: (at 1,4,12 in 18,0; contains blocks 288,0,0 to 303,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 3680803 game time, 4016568 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: 70 total; [EntityPixelmon['Diglett'/256, l='MpServer', x=-460,50, y=34,00, z=339,50], EntityPixelmon['Rattata'/129, l='MpServer', x=-461,50, y=72,00, z=258,84], EntityPixelmon['Oddish'/130, l='MpServer', x=-466,50, y=72,00, z=259,50], EntityPixelmon['Shuckle'/131, l='MpServer', x=-465,50, y=53,00, z=260,50], EntityPixelmon['Aron'/265, l='MpServer', x=-443,50, y=44,00, z=270,50], EntityPixelmon['Shuckle'/266, l='MpServer', x=-454,50, y=5,00, z=308,50], EntityPixelmon['Solrock'/267, l='MpServer', x=-487,50, y=23,00, z=375,50], EntityPixelmon['Teddiursa'/274, l='MpServer', x=-432,50, y=78,00, z=296,50], NPCTrader['Trader'/36, l='MpServer', x=-453,30, y=63,00, z=416,01], NPCTrader['Trader'/37, l='MpServer', x=-452,15, y=64,00, z=417,30], EntityItem['item.item.beetroot_seeds'/38, l='MpServer', x=-495,87, y=61,00, z=328,87], EntityPlayerSP['MaximusLi'/35, l='MpServer', x=-519,42, y=64,00, z=351,90], EntityHorse['Skeleton Horse'/40, l='MpServer', x=-473,12, y=62,19, z=371,21], NPCTrader['Trader'/41, l='MpServer', x=-469,70, y=62,58, z=362,30], EntityItem['item.item.seeds'/42, l='MpServer', x=-502,56, y=63,00, z=328,97], NPCTrader['Trader'/43, l='MpServer', x=-514,08, y=64,00, z=335,24], EntityHorse['Skeleton Horse'/44, l='MpServer', x=-529,39, y=63,00, z=350,04], NPCTrader['Trader'/45, l='MpServer', x=-548,25, y=70,00, z=259,80], NPCTrader['Trader'/46, l='MpServer', x=-601,07, y=73,00, z=337,18], NPCTrader['Trader'/48, l='MpServer', x=-585,70, y=67,00, z=277,52], NPCTrader['Trader'/49, l='MpServer', x=-612,97, y=68,00, z=317,70], NPCTrader['Trader'/53, l='MpServer', x=-447,50, y=62,15, z=446,89], EntityPixelmon['Goldeen'/56, l='MpServer', x=-477,77, y=53,58, z=390,83], EntityPixelmon['Goldeen'/57, l='MpServer', x=-534,49, y=53,60, z=399,65], EntityPixelmon['Goldeen'/58, l='MpServer', x=-482,16, y=53,42, z=411,91], EntityPixelmon['Goldeen'/59, l='MpServer', x=-481,05, y=53,40, z=380,74], EntityPixelmon['Abra'/66, l='MpServer', x=-426,50, y=76,00, z=317,50], EntityPixelmon['Staryu'/67, l='MpServer', x=-556,55, y=42,52, z=408,97], EntityPixelmon['Staryu'/68, l='MpServer', x=-554,46, y=48,03, z=436,50], EntityPixelmon['Starly'/69, l='MpServer', x=-523,97, y=64,00, z=266,53], EntityPixelmon['Magikarp'/198, l='MpServer', x=-607,46, y=58,46, z=373,90], EntityPixelmon['Corphish'/71, l='MpServer', x=-537,36, y=66,00, z=268,50], EntityPixelmon['Fearow'/72, l='MpServer', x=-577,98, y=77,50, z=363,82], EntityPixelmon['Milotic'/73, l='MpServer', x=-493,89, y=46,00, z=411,93], EntityPixelmon['Shuckle'/201, l='MpServer', x=-617,50, y=16,00, z=297,50], EntityPixelmon['Tentacool'/74, l='MpServer', x=-534,94, y=56,50, z=304,63], EntityPixelmon['Pidgey'/81, l='MpServer', x=-606,83, y=74,53, z=291,92], EntityPixelmon['Oddish'/82, l='MpServer', x=-605,48, y=70,00, z=271,90], EntityPixelmon['Oddish'/83, l='MpServer', x=-599,50, y=71,00, z=284,50], EntityPixelmon['Goldeen'/84, l='MpServer', x=-467,50, y=54,01, z=290,50], EntityPixelmon['Shuckle'/212, l='MpServer', x=-588,50, y=16,00, z=382,50], EntityPixelmon['Goldeen'/85, l='MpServer', x=-490,26, y=53,37, z=284,50], EntityPixelmon['Goldeen'/86, l='MpServer', x=-472,14, y=55,00, z=306,50], EntityPixelmon['Weepinbell'/217, l='MpServer', x=-600,13, y=72,00, z=263,90], EntityPixelmon['Bellsprout'/219, l='MpServer', x=-595,50, y=72,00, z=265,50], EntityPixelmon['Horsea'/92, l='MpServer', x=-490,55, y=55,11, z=287,75], EntityPixelmon['Tentacool'/94, l='MpServer', x=-609,21, y=56,43, z=434,63], EntityPixelmon['Togetic'/95, l='MpServer', x=-618,50, y=67,00, z=278,50], EntityPixelmon['Wingull'/97, l='MpServer', x=-556,18, y=64,00, z=291,32], EntityPixelmon['Wooper'/227, l='MpServer', x=-423,25, y=57,00, z=377,48], EntityPixelmon['Aron'/100, l='MpServer', x=-488,50, y=34,00, z=381,50], EntityPixelmon['Wingull'/228, l='MpServer', x=-478,45, y=66,54, z=265,56], EntityPixelmon['Wingull'/229, l='MpServer', x=-475,37, y=66,00, z=265,98], EntityPixelmon['Wingull'/230, l='MpServer', x=-477,85, y=65,92, z=265,36], EntityPixelmon['Krabby'/231, l='MpServer', x=-482,50, y=64,00, z=267,50], EntityPixelmon['Azumarill'/104, l='MpServer', x=-594,33, y=70,00, z=294,88], EntityPixelmon['Psyduck'/110, l='MpServer', x=-489,50, y=68,00, z=341,74], EntityPixelmon['Ivysaur'/113, l='MpServer', x=-594,48, y=72,00, z=314,06], EntityPixelmon['Tentacool'/241, l='MpServer', x=-497,16, y=51,53, z=302,10], EntityPixelmon['Tentacool'/242, l='MpServer', x=-479,16, y=57,00, z=309,50], EntityPixelmon['Kadabra'/114, l='MpServer', x=-617,60, y=72,00, z=295,36], EntityPixelmon['Tentacool'/243, l='MpServer', x=-527,35, y=52,33, z=326,09], EntityPixelmon['Wingull'/116, l='MpServer', x=-497,71, y=72,00, z=341,76], EntityPixelmon['Wingull'/117, l='MpServer', x=-511,62, y=76,00, z=354,53], EntityPixelmon['Goldeen'/245, l='MpServer', x=-497,46, y=52,70, z=294,84], EntityPixelmon['Goldeen'/246, l='MpServer', x=-485,09, y=54,54, z=281,29], EntityPixelmon['Wingull'/120, l='MpServer', x=-511,50, y=66,00, z=342,50], EntityPixelmon['Goldeen'/249, l='MpServer', x=-477,75, y=56,30, z=307,06], EntityPixelmon['Aggron'/252, l='MpServer', x=-529,50, y=29,00, z=358,50], EntityPixelmon['Diglett'/254, l='MpServer', x=-460,50, y=34,00, z=340,50]]
Retry entities: 0 total; []
Server brand: fml,forge
Server type: Integrated singleplayer server
Stacktrace:
at net.minecraft.client.multiplayer.WorldClient.func_72914_a(WorldClient.java:415)
at net.minecraft.client.Minecraft.func_71396_d(Minecraft.java:2660)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:400)
at net.minecraft.client.main.Main.main(SourceFile:124)
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)

-- System Details --
Details:
Minecraft Version: 1.10.2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_101, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 755347840 bytes (720 MB) / 1891098624 bytes (1803 MB) up to 3207856128 bytes (3059 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx3G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 3, allocated: 12, tallocated: 94
FML: MCP 9.32 Powered by Forge 12.18.1.2075 7 mods loaded, 7 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{9.19} [Minecraft Coder Pack] (minecraft.jar)
UCHIJAAAA FML{8.0.99.99} [Forge Mod Loader] (forge-1.10.2-12.18.1.2075.jar)
UCHIJAAAA Forge{12.18.1.2075} [Minecraft Forge] (forge-1.10.2-12.18.1.2075.jar)
UCHIJAAAA pixelmon{5.0.0-beta7} [Pixelmon] (Pixelmon-1.10.2-5.0.0-beta7-universal.jar)
UCHIJAAAA gameshark{4.2.0} [Gameshark (Pixelmon)] (Gameshark-1.10.2-4.2.0-universal.jar)
UCHIJAAAA XaeroMinimap{1.10.5} [Xaero's Minimap] (Xaeros_Minimap_1.10.5_Forge_1.10.2.jar)
UCHIJAAAA XaeroWorldMap{1.2} [Xaero's World Map] (XaerosWorldMap_b1.3_Forge_1.10.2.jar)
Loaded coremods (and transformers):
GL info: ' Vendor: 'NVIDIA Corporation' Version: '4.5.0 NVIDIA 372.70' Renderer: 'GeForce GT 750M/PCIe/SSE2'
Launched Version: 1.10.2-forge1.10.2-12.18.1.2075
LWJGL: 2.9.4
OpenGL: GeForce GT 750M/PCIe/SSE2 GL version 4.5.0 NVIDIA 372.70, 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)
CPU: 8x Intel(R) Core(TM) i7-4700MQ CPU @ 2.40GHz

Easy fix, i'll try to get it sorted by the weekend

Closing as this is expired and resolved.