Minecraft Forge Server wont start when trying to add ram(MAC)

neji813 · February 22, 2018

Hello, I'm new to making a modded minecraft server and just recently started looking into how to make/run one on mac. I was able to create a regular Vanilla server and run it smoothly without any errors. I eventually moved on to running modded minecraft forge servers and ran into an error message on the mac terminal and I am unsure where to go or what to do. I have a early 2008 mac running El capitain. The mod server file I used to download the forge server is 1.12.2 (forge - 14.23.2.2611). I used this download then followed the same instructions provided to me by a youtube video on how to start a minecraft server.I then proceeded to start the Start.command file I created to add more ram and ran into this error message:

A problem occurred running the Server launcher.java.lang.reflect.InvocationTargetException
   at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.base/java.lang.reflect.Method.invoke(Method.java:564)
   at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:62)
   at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:31)
Caused by: java.lang.ClassCastException: java.base/jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to java.base/java.net.URLClassLoader
   at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
   at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
   ... 6 more
logout
Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.

Cadiboo · February 22, 2018

That crash log tells me that there was an error... and exactly nothing else.
What mods are you running on the sever (if none tell me none)?

Are you able to run a normal minecraft server on your computer?

What tutorial did you follow?

What is inside your Start.command file

What version is your Java?

Choonster · February 22, 2018

You're using Java 9, which isn't supported by Forge. You need to use Java 8 instead.

In future, post the FML log (fml-server-latest.log in the server directory) in a spoiler or on Gist.

Edited February 22, 2018 by Choonster

neji813 · February 22, 2018

@Cadiboo I havent added any mods yet. Yes i am able to run a normal minecraft server on the computer. Here is the links to the videos I followed:

start.command file has this text inside:

#!/bin/bash

cd "$(dirname "$0")"

exec java Xms1024M -Xmx1024M -jar forge-1.12.2-14.23.2.2611-universal.jar nogui

And the version of java im using is Version 8 Update 161 (build 1.8.0_161-b12)

Edited February 22, 2018 by neji813

Cadiboo · February 22, 2018

1 minute ago, neji813 said:

Version 8 Update 161 (build 1.8.0_161-b12)

Java should be Version 8 Update 151 8u151

neji813 · February 22, 2018

Ok. How would i go about changing it to that? Also is it Runtime environment or development kit for the java download version?

Edited February 22, 2018 by neji813

Cadiboo · February 22, 2018

3 minutes ago, neji813 said:

Ok. How would i go about changing it to that? Also is it Runtime environment or development kit for the java download version?

I dont believe you need the Development kit, but I've always downloaded it just to be safe (it includes normal java in it) and its worked fine

How to change it:

It could be complicated, you should be able to change it with commands but that didn't work for me (MacBook Pro 2013) so I deleted java completely then installed the right java

Java 8u151:

http://www.oracle.com/technetwork/java/javase/downloads/java-archive-javase8-2177648.html

MAKE SURE you download 8u151 not 8u152 (8u151 is the second release from the to, and the 3rd item from the top)

neji813 · February 22, 2018

29 minutes ago, Cadiboo said:

I dont believe you need the Development kit, but I've always downloaded it just to be safe (it includes normal java in it) and its worked fine

How to change it:

It could be complicated, you should be able to change it with commands but that didn't work for me (MacBook Pro 2013) so I deleted java completely then installed the right java

Java 8u151:

http://www.oracle.com/technetwork/java/javase/downloads/java-archive-javase8-2177648.html

MAKE SURE you download 8u151 not 8u152 (8u151 is the second release from the to, and the 3rd item from the top)

So I deleted my java and reinstalled the files from the website download page you provided. I proceeded to try and attempt to start the server through the start.command file again and received the same message in the terminal I posted earlier.

neji813 · February 22, 2018

1 hour ago, Choonster said:

You're using Java 9, which isn't supported by Forge. You need to use Java 8 instead.

In future, post the FML log (fml-server-latest.log in the server directory) in a spoiler or on Gist.

fml-server-latest.log

Choonster · February 22, 2018

39 minutes ago, neji813 said:

fml-server-latest.log

That wasn't in a spoiler or on Gist.

There's no error in that log, because you're running the server with Java 8. Your original crash was caused by running the server with Java 9.

neji813 · February 22, 2018

1 minute ago, Choonster said:

That wasn't in a spoiler or on Gist.

There's no error in that log, because you're running the server with Java 8. Your original crash was caused by running the server with Java 9.

How do you place it in a spoiler and I was looking in the folder an that was the latest.I just reinstalled java 8 151 and it still didnt work

Choonster · February 22, 2018

Just now, neji813 said:

How do you place it in a spoiler

Use the eye icon in the post editor.

Just now, neji813 said:

and I was looking in the folder an that was the latest.I just reinstalled java 8 151 and it still didnt work

Delete the FML log and then run the server again, making sure to use Java 8. If it still crashes, post the new FML log.

neji813 · February 22, 2018

15 minutes ago, Choonster said:

Use the eye icon in the post editor.

Delete the FML log and then run the server again, making sure to use Java 8. If it still crashes, post the new FML log.

Ok so I followed your steps and I started the server from the start.command file and Received this message from the mac terminal and NO logs were created:

A problem occurred running the Server launcher.java.lang.reflect.InvocationTargetException

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

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.base/java.lang.reflect.Method.invoke(Method.java:564)

at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:62)

at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:31)

Caused by: java.lang.ClassCastException: java.base/jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to java.base/java.net.URLClassLoader

at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)

at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

... 6 more

logout

Saving session...

...copying shared history...

...saving history...truncating history files...

...completed.

[Process completed]

neji813 · February 22, 2018

So after I decided to run the server straight from the .Jar forge file and it runs smooth but the only set back is the MAJOR lack of ram. Is there any way I could fix that issue with the terminal "start.command" file?

neji813 · February 22, 2018

1 minute ago, diesieben07 said:

You are still running with Java 9.

How? I deleted the java files from my computer and then reinstalled from the Java website version 8 151. Then checked the version in my system preferences and it says version 8 151.

neji813 · February 22, 2018

How do I fix this?

neji813 · February 22, 2018

1 minute ago, diesieben07 said:

Uninstall Java 9. Install Java 8.

How do I do that? I looked into it myself before and was unsuccessful with it. Can you help me with the uninstall process?

neji813 · February 23, 2018

Ok so I uninstalled Java 9 with the commands from terminal straight from this website here:

https://gist.github.com/schnell18/bcb9833f725be22f6acd01f94b486392

and then reinstalled java 8. I then removed all of my files regarding forge craft then reinstalled everything and start the "start.command" file then received this error message:

Spoiler