Latest available radixcore for 1.7.2 runs fine alone with the latest forge available installed into MC 1.7.2. As soon as I put the last MCA-4.1.2 MC-1.7.2.zip release in it crashes MC soon after launch. Any ideas?

---- Minecraft Crash Report ----
// Ouch. That hurt :(

Time: 8/2/15 11:32 PM
Description: Initializing game

java.lang.NoClassDefFoundError: com/radixshock/radixcore/core/IUpdateChecker
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:278)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:420)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
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(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:118)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:491)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:204)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:815)
at net.minecraft.client.main.Main.main(SourceFile:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
Caused by: java.lang.ClassNotFoundException: com.radixshock.radixcore.core.IUpdateChecker
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 35 more
Caused by: java.lang.NullPointerException
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:180)
... 37 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(Class.java:278)
at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:420)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
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(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.google.common.eventbus.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:118)
at cpw.mods.fml.common.Loader.loadMods(Loader.java:491)
at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:204)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:467)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:815)
at net.minecraft.client.main.Main.main(SourceFile:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.7.2
Operating System: Linux (amd64) version 3.16.7.15-1-MANJARO
Java Version: 1.7.0_85, Oracle Corporation
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 346758896 bytes (330 MB) / 512032768 bytes (488 MB) up to 6429081600 bytes (6131 MB)
JVM Flags: 5 total; -Xmx6G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
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 v9.03 FML v7.2.217.1147 Minecraft Forge 10.12.2.1147 5 mods loaded, 5 mods active
mcp{9.03} Minecraft Coder Pack Unloaded->Constructed
FML{7.2.217.1147} Forge Mod Loader Unloaded->Constructed
Forge{10.12.2.1147} Minecraft Forge Unloaded->Constructed
radixcore{1.2.0} RadixCore Unloaded->Constructed
mca{4.1.2} Minecraft Comes Alive Unloaded
Launched Version: 1.7.2-Forge10.12.2.1147
LWJGL: 2.9.0
OpenGL: GeForce GTX 760/PCIe/SSE2 GL version 4.5.0 NVIDIA 352.30, NVIDIA Corporation
Is Modded: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Packs: [[1.7]_R3D.CRAFT_N_MAPS_SR-256x_v0.1.0.zip, [1.7]_R3D.CRAFT_SR-256x_v0.1.9.zip]
Current Language: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: ERROR NullPointerException: null
Anisotropic Filtering: Off (1)

Not latest version.

Yes, it is recommended to update to the late/latest version, due to many fixes and fun features.

Um, it is the latest version for 1.7.2.

Reply: @Orange1861

The point is on the minecraft version, not the MCA one. The late version of minecraft is 1.7.x, most are 1.7.10, > 1.8. The difference is MCA version is related what minecraft version are you playing on.

So eGax would recommended to upgrade to the late minecraft version, if possible, as many people do. If you can't upgrade due to a reason, the 1.7.2 MCA version will be upgraded like any 1.7.10 and 1.8 versions, if requested.

MCA for 1.7.2 is not supported, sorry.