If I have AE2 installed Minecraft crashes on startup. AE version: rv0_stable_10 Mekanism version:7.0.0.75
Crash report:

---- Minecraft Crash Report ----
// Ooh. Shiny.

Time: 2014.08.07. 2:51
Description: Initializing game

java.lang.NoClassDefFoundError: mekanism/common/tile/TileEntityChanceMachine
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.ProxyInjector.inject(ProxyInjector.java:59)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:492)
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 com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:208)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187)
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 com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:118)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:492)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:204)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:480)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:867)
at net.minecraft.client.main.Main.main(SourceFile:148)
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:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
Caused by: java.lang.ClassNotFoundException: mekanism.common.tile.TileEntityChanceMachine
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:188)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 36 more
Caused by: java.lang.NoClassDefFoundError: mekanism/common/tile/TileEntityBasicMachine
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:180)
... 38 more
Caused by: java.lang.ClassNotFoundException: mekanism.common.tile.TileEntityBasicMachine
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:99)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 42 more

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

-- Head --
Stacktrace:
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at cpw.mods.fml.common.ProxyInjector.inject(ProxyInjector.java:59)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:492)
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 com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:208)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:187)
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 com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:118)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:492)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:204)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:480)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:867)
at net.minecraft.client.main.Main.main(SourceFile:148)
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:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.7.10
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_65, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 92209760 bytes (87 MB) / 258809856 bytes (246 MB) up to 2134114304 bytes (2035 MB)
JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M -XX:PermSize=512m -XX:MaxPermSize=1024m
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP v9.05 FML v7.10.25.1199 Minecraft Forge 10.13.0.1199 39 mods loaded, 39 mods active
mcp{9.05} Minecraft Coder Pack Unloaded->Constructed
FML{7.10.25.1199} Forge Mod Loader Unloaded->Constructed
Forge{10.13.0.1199} Minecraft Forge Unloaded->Constructed
AppliedEnergistics2-Core{rv0-stable-10} AppliedEnergistics2 Core Unloaded->Constructed
CodeChickenCore{1.0.2.9} CodeChicken Core Unloaded->Constructed
{000} CoFH ASM Data Initialization Unloaded->Constructed
NotEnoughItems{1.0.2.15} Not Enough Items Unloaded->Constructed
OpenModsCore{@Version@} OpenModsCore Unloaded->Constructed
bspkrsCore{6.9} bspkrsCore Unloaded->Constructed
Treecapitator{1.7.2} Treecapitator Unloaded->Constructed
ForgeMultipart{1.1.0.297} Forge Multipart Unloaded->Constructed
CoFHCore{1.7.10R3.0.0B3} CoFH Core Unloaded->Constructed
Mekanism{7.0.0} Mekanism Unloaded
appliedenergistics2{rv0-stable-10} Applied Energistics 2 Unloaded
bdlib{1.4.1.7} BD Lib Unloaded
Forestry{2.4.2.37} Forestry for Minecraft Unloaded
gendustry{1.3.0.7} GenDustry Unloaded
iChunUtil{4.0.0} iChunUtil Unloaded
MapWriter{2.1.1} MapWriter Unloaded
MekanismGenerators{7.0.0} MekanismGenerators Unloaded
MekanismTools{7.0.0} MekanismTools Unloaded
NEIAddons{1.12.0.4} NEI Addons Unloaded
NEIAddons|ExtraBees{1.12.0.4} NEI Addons: Extra Bees Unloaded
NEIAddons|Forestry{1.12.0.4} NEI Addons: Forestry Unloaded
NEIAddons|CraftingTables{1.12.0.4} NEI Addons: Crafting Tables Unloaded
NEIAddons|ExNihilo{1.12.0.4} NEI Addons: Ex Nihilo Unloaded
OpenMods{0.6} OpenMods Unloaded
ProjRed|Core{4.4.5.44} ProjectRed Unloaded
ProjRed|Transmission{4.4.5.44} ProjectRed-Transmission Unloaded
ProjRed|Transportation{4.4.5.44} ProjectRed-Transportation Unloaded
ProjRed|Exploration{4.4.5.44} ProjectRed-Exploration Unloaded
ProjRed|Compatibility{4.4.5.44} ProjectRed-Compatibility Unloaded
ProjRed|Integration{4.4.5.44} ProjectRed-Integration Unloaded
ProjRed|Illumination{4.4.5.44} ProjectRed-Illumination Unloaded
ProjRed|Expansion{4.4.5.44} ProjectRed-Expansion Unloaded
Waila{1.5.2_1.7.2} Waila Unloaded
McMultipart{1.1.0.297} Minecraft Multipart Plugin Unloaded
aobd{2.2.2} Another One Bites The Dust Unloaded
ForgeMicroblock{1.1.0.297} Forge Microblocks Unloaded
Launched Version: 1.7.10-Forge10.13.0.1199
LWJGL: 2.9.1
OpenGL: AMD Radeon HD 5700 Series GL version 4.3.12798 Compatibility Profile Context 13.350.1005.0, ATI Technologies Inc.
GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

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)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: Off (1)

Try build 87, it should fix this. If not, pastebin the fml-client-latest.log for me please.

Correct, this was fixed.