(I don´t know why I couldn´t register on Github before but now it worked)

My Issue is that when I load Harvest Festival alone in Minecraft, it works. As soon as I load in another mod (doesn´t matter which one, tried with different ones) It crashes.

I use latest version of Forge (not recommend)

Crash Report:

[net.minecraft.init.Bootstrap:func_179870_a:560]: ---- Minecraft Crash Report ----

WARNING: coremods are present:
HFTransformer (Harvest-Festival-1.10.2-0.6.0-213.jar)
Contact their authors BEFORE contacting forge

// Uh... Did I do that?

Time: 28.04.17 21:12
Description: There was a severe problem during mod loading that has caused the game to fail

net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from Harvest Festival (harvestfestival)
Caused by: java.lang.NoClassDefFoundError: com/pam/harvestcraft/blocks/blocks/PresserBlock
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:260)
at joshie.harvest.core.proxy.HFCommonProxy.setup(HFCommonProxy.java:58)
at joshie.harvest.HarvestFestival.preInit(HarvestFestival.java:36)
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.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:616)
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 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 net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:243)
at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:221)
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 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 net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:145)
at net.minecraftforge.fml.common.Loader.preinitializeMods(Loader.java:624)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:259)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:439)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:351)
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)
Caused by: java.lang.ClassNotFoundException: com.pam.harvestcraft.blocks.blocks.PresserBlock
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 41 more
Caused by: java.lang.NullPointerException

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

-- System Details --
Details:
Minecraft Version: 1.10.2
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 622805040 bytes (593 MB) / 1939079168 bytes (1849 MB) up to 8375238656 bytes (7987 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx8G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn2G
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP 9.32 Powered by Forge 12.18.3.2281 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
UCH mcp{9.19} [Minecraft Coder Pack] (minecraft.jar)
UCH FML{8.0.99.99} [Forge Mod Loader] (forge-1.10.2-12.18.3.2281.jar)
UCH Forge{12.18.3.2281} [Minecraft Forge] (forge-1.10.2-12.18.3.2281.jar)
UCH mercurius_updater{1.0} [mercurius_updater] (MercuriusUpdater-1.10.2.jar)
UCE harvestfestival{0.6.0} [Harvest Festival] (Harvest-Festival-1.10.2-0.6.0-213.jar)
UCH hfaddon{0.6.0 Alpha} [HF Addon] (fhaddon-0.6.0.jar)
Loaded coremods (and transformers):
HFTransformer (Harvest-Festival-1.10.2-0.6.0-213.jar)
joshie.harvest.asm.HFTransformer
GL info: ' Vendor: 'NVIDIA Corporation' Version: '4.5.0 NVIDIA 372.90' Renderer: 'GeForce GTX 770/PCIe/SSE2'

Ahhh there we go. You have the hfaddon which only works with 0.5 version of the mod :), as well as that mod needing harvestcraft. At least that's what this crash is saying.

I was using the right version of Hfaddon but I was missing Harvestcraft. It works now thank you very much!

Oh i didn't know the addon had been updated :). Glad you got it working :D