Configuration with Minecraft - Minecraft (feed The Beast Infinity 1.7)

System Information

Field Value
Operating System Linux - Debian GNU/Linux 11 on x86_64
Product AMP ‘Decadeus’ v2.4.6.6 (Mainline)
Virtualization QEMU_KVM
Application Minecraft
Module MinecraftModule
Running in Container No
Current State Ready

Problem Description


Been Having The issue Where I follow the steps to setup a FTB Infinity 1.7 Server And Everytime i try none of the mods load and if you try to create any item from a mod it fails to do so, and none of the starting items from the modpack books ect, load in with you as they should.

Reproduction Steps

  • Created Instance
  • Set Server To Feed The Beast New
  • Selected Feed The Beast Infinity 1.7
  • Set RAM 16GB
  • Updated Server And Started
  • Connected To Server
  • Server Runs But No Modpacks Work Whatsoever

The FTB download API doesn’t provide version info.
So after you install the pack you need to set the Server Type to Forge and the version to the version of Forge the pack uses, hit Download/Update, then leave the Jar as [Autoselect].
Make sure to delete the world folder though, since it’s been generated in vanilla.

Yeah attempted that whenever i do i get a client version misatch with 1.7.10 Forge.jar

It might not use the most recent version of Forge 1.7.10, you’ll need to double check that you’re using the right subversion, usually you can see that sort of info on your client.

so i went and got the server jar from FTB directly cause the forge method you explained causes the server to outright fail on hostinger, and this is the msg i get when starting with it

A problem occurred running the Server

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(

at java.base/java.lang.reflect.Method.invoke(


at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(

Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class (jdk.internal.loader.ClassLoaders$AppClassLoader and are in module java.base of loader ‘bootstrap’)

at net.minecraft.launchwrapper.Launch.(

at net.minecraft.launchwrapper.Launch.main(

Ah you need to use Java 8 with 1.7.10 (ConfigurationJava and Memory)

Yeah. its set and has been set to Java 8 (Hotspot) whole time.

If that’s the case then the setting might be stuck under the hood.
Set the Java version to something else (like 17), wait 5-10 seconds, then change it back to 8.

so i think the jdk 8 did something cause stuffs different now, new error msg.
also everyhting on my console changed before it was installing the FTB 1.7.0 pack through the Feed the beat (New) and now it only shows on legacy. which seems correct. but this is getting pretty aggravating for something thats sold as a one touch setup service lol. but thanks for all the help so far.

A problem occurred running the Server

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(

at sun.reflect.DelegatingMethodAccessorImpl.invoke(

at java.lang.reflect.Method.invoke(


at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(

Caused by: java.lang.NoClassDefFoundError: org/apache/logging/log4j/Level

at net.minecraft.launchwrapper.Launch.launch(

at net.minecraft.launchwrapper.Launch.main(

… 6 more

Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Level


at java.lang.ClassLoader.loadClass(

at sun.misc.Launcher$AppClassLoader.loadClass(

at java.lang.ClassLoader.loadClass(

Yeah, really Hostinger should be helping you (I’ve heard their support is great /s), this is the AMP community support forum.
I’d say nuke the mod files and Jars, then start things from the top:

  • Install the pack via FTB new source
    • Note: If you use FTB old source you need to delete any server Jars, then install Forge
      (There’s some dead MC server download links that the old installers try to use)
  • Change the Server Type back to Forge
  • Set Forge Version to the right version of Forge 1.7.10
  • Hit Download/Update
  • Cross your fingers and start

It just came to me while I was writing those steps, the weird reflection errors also show when there’s 0 byte MC Jars in the mix, you can thank FTB’s old installers for that one (that one took me ages to debug the first time I came across the issue)

Yeah same thing trying that method, and made sure its the correct version, same java errors as last posted, think ill just give up on it. but i appreciate all the help. i do IT for a living last thing i feel like doing is the 15 hours of troubleshooting on my only days off to get a minecraft server going for 2 people ill just use something thats not FTB and reliable ive had no issues with most of those packs lol. but thanks again.

Hey, yeah that’s completely valid, always glad to help out!
If you run into anything funky in your modding travels, I got a post on debugging common Forge issues:

Wanted to update you for all the help, went with a newer FTB Pack Than i was using and using your FAQ for Jar server not found was eaisly able to get it running, due to the JVM arguments on FTB 1.7.10-1614 i think its actually some kinda issue with the JAR the AMP Server is using and had same issue with FTB one provided as i FTPd it to try that too, seems the install was janky at best cause when i did the new modpack i got alot more console feedback than previous pack. Thank for the help last night and stay safe.

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