我在尝试安装forge1.12.2-14.23.5.2838版本

云主机：阿里云学生轻量机（1核;2G;5M带宽;30M峰值带宽）
系统：Ubuntu 16.04.3 LTS(Py2.7.12)
forge的文件是我从win系统下载后上传到服务器的
win系统java版本为：java8
服务器java版本为java开发14
但是他提示了以下错误，请问如何解决：
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:70)
        at net.minecraftforge.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:34)
Caused by: java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
        at net.minecraft.launchwrapper.Launch.<init>(Launch.java:34)
        at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
        ... 6 more

需要其他消息我会尽量提供的，请大神看到后helphelp我

降级到java8试试
既然装了ubuntu系统具体怎么操作应该就不用我细说了吧？

ok，我先试一下

.minecraft\logs\报错的log这个发一下
不然很难看出

这是今天报的错，我找不到今天的文件
以下是lates.logt文件的内容：
[05:11:44] [Server console handler/ERROR]: Exception handling console input
java.io.IOException: Input/output error
        at java.io.FileInputStream.readBytes(Native Method) ~[?:?]
        at java.io.FileInputStream.read(FileInputStream.java:272) ~[?:?]
        at java.io.BufferedInputStream.read1(BufferedInputStream.java:282) ~[?:?]
        at java.io.BufferedInputStream.read(BufferedInputStream.java:343) ~[?:?]
        at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:297) ~[?:?]
        at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:339) ~[?:?]
        at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:188) ~[?:?]
        at java.io.InputStreamReader.read(InputStreamReader.java:181) ~[?:?]
        at java.io.BufferedReader.fill(BufferedReader.java:161) ~[?:?]
        at java.io.BufferedReader.readLine(BufferedReader.java:326) ~[?:?]
        at java.io.BufferedReader.readLine(BufferedReader.java:392) ~[?:?]
        at nz$2.run(SourceFile:100) [minecraft_server.1.12.2.jar:?]
[05:11:44] [Server Shutdown Thread/INFO]: Stopping server
[05:11:44] [Server Shutdown Thread/INFO]: Saving players
[05:11:44] [Server Shutdown Thread/INFO]: Saving worlds
[05:11:44] [Server Shutdown Thread/INFO]: Saving chunks for level 'world'/overworld
[05:11:44] [Server Shutdown Thread/INFO]: Saving chunks for level 'world'/the_nether
[05:11:44] [Server Shutdown Thread/INFO]: Saving chunks for level 'world'/the_end

我不认为是服务器端出现的问题，因为在安装forge之前，服务器端都是正常运行的

感谢您，我已经更换为8u251开发版了
现在我能正常进入地图了，但是他弹出了大量信息，我觉得其中还可能有错误，请帮忙检查一下
root@iZuf60ea84sfgqtqg5wpvcZ:~# cd /MC
root@iZuf60ea84sfgqtqg5wpvcZ:/MC# java -Xms256M -Xmx512M -jar /MC/forge-1.12.2-14.23.5.2838-installer.jar nogui
Error: Unable to access jarfile /MC/forge-1.12.2-14.23.5.2838-installer.jar
root@iZuf60ea84sfgqtqg5wpvcZ:/MC# java -Xms256M -Xmx512M -jar /MC/forge-1.12.2-14.23.5.2838-universal.jar nogui
[15:25:36] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLServerTweaker
[15:25:36] [main/INFO] [LaunchWrapper]: Using primary tweak class name net.minecraftforge.fml.common.launcher.FMLServerTweaker
[15:25:36] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLServerTweaker
[15:25:36] [main/INFO] [FML]: Forge Mod Loader version 14.23.5.2838 for Minecraft 1.12.2 loading
[15:25:36] [main/INFO] [FML]: Java is Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_251, running on Linux:amd64:4.4.0-93-generic, installed at /JAVA/jdk1.8.0_251/jre
[15:25:36] [main/INFO] [FML]: Searching /MC/./mods for mods
[15:25:36] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[15:25:36] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLDeobfTweaker
[15:25:36] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[15:25:36] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[15:25:36] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[15:25:40] [main/INFO] [FML]: Found valid fingerprint for Minecraft Forge. Certificate fingerprint e3c3d50c7c986df74c645c0ac54639741c90a557
[15:25:40] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[15:25:40] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLDeobfTweaker
[15:25:41] [main/INFO] [LaunchWrapper]: Loading tweak class name net.minecraftforge.fml.common.launcher.TerminalTweaker
[15:25:41] [main/INFO] [LaunchWrapper]: Calling tweak class net.minecraftforge.fml.common.launcher.TerminalTweaker
[15:25:42] [main/INFO] [LaunchWrapper]: Launching wrapped minecraft {net.minecraft.server.MinecraftServer}
[15:25:50] [Server thread/INFO] [minecraft/DedicatedServer]: Starting minecraft server version 1.12.2
[15:25:50] [Server thread/WARN] [minecraft/DedicatedServer]: To start the server with more ram, launch it as "java -Xmx1024M -Xms1024M -jar minecraft_server.jar"
[15:25:50] [Server thread/INFO] [FML]: MinecraftForge v14.23.5.2838 Initialized
[15:25:50] [Server thread/INFO] [FML]: Starts to replace vanilla recipe ingredients with ore ingredients.
[15:25:51] [Server thread/INFO] [FML]: Invalid recipe found with multiple oredict ingredients in the same ingredient...
[15:25:51] [Server thread/INFO] [FML]: Replaced 1227 ore ingredients
[15:25:51] [Server thread/INFO] [FML]: Config directory created successfully
[15:25:51] [Server thread/INFO] [FML]: Searching /MC/./mods for mods
[15:25:52] [Server thread/INFO] [FML]: Forge Mod Loader has identified 4 mods to load
[15:25:52] [Server thread/WARN] [FML]: Missing English translation for FML: assets/fml/lang/en_us.lang
[15:25:53] [Server thread/INFO] [FML]: Attempting connection with missing mods [minecraft, mcp, FML, forge] at CLIENT
[15:25:53] [Server thread/INFO] [FML]: Attempting connection with missing mods [minecraft, mcp, FML, forge] at SERVER
[15:25:54] [Server thread/INFO] [FML]: Processing ObjectHolder annotations
[15:25:54] [Server thread/INFO] [FML]: Found 1169 ObjectHolder annotations
[15:25:54] [Server thread/INFO] [FML]: Identifying ItemStackHolder annotations
[15:25:54] [Server thread/INFO] [FML]: Found 0 ItemStackHolder annotations
[15:25:54] [Server thread/INFO] [FML]: Configured a dormant chunk cache size of 0
[15:25:54] [Server thread/INFO] [FML]: Applying holder lookups
> [15:25:54] [Forge Version Check/INFO] [forge.VersionCheck]: [forge] Starting version check at http://files.minecraftforge.net/ ... romotions_slim.json
[15:25:54] [Server thread/INFO] [FML]: Holder lookups applied
[15:25:54] [Server thread/INFO] [FML]: Applying holder lookups
[15:25:54] [Server thread/INFO] [FML]: Holder lookups applied
[15:25:54] [Server thread/INFO] [FML]: Applying holder lookups
[15:25:54] [Server thread/INFO] [FML]: Holder lookups applied
[15:25:54] [Server thread/INFO] [FML]: Applying holder lookups
[15:25:54] [Server thread/INFO] [FML]: Holder lookups applied
[15:25:54] [Server thread/INFO] [FML]: Injecting itemstacks
[15:25:54] [Server thread/INFO] [FML]: Itemstack injection complete
[15:25:54] [Server thread/INFO] [minecraft/DedicatedServer]: Loading properties
[15:25:54] [Server thread/INFO] [minecraft/DedicatedServer]: Default game type: SURVIVAL
[15:25:54] [Server thread/INFO] [minecraft/DedicatedServer]: Generating keypair
[15:25:54] [Server thread/INFO] [minecraft/DedicatedServer]: Starting Minecraft server on *:25565
[15:25:55] [Server thread/INFO] [minecraft/NetworkSystem]: Using epoll channel type
[15:25:55] [Server thread/WARN] [minecraft/DedicatedServer]: **** SERVER IS RUNNING IN OFFLINE/INSECURE MODE!
[15:25:55] [Server thread/WARN] [minecraft/DedicatedServer]: The server will make no attempt to authenticate usernames. Beware.
[15:25:55] [Server thread/WARN] [minecraft/DedicatedServer]: While this makes the game possible to play without internet access, it also opens up the ability for hackers to connect with any username they choose.
[15:25:55] [Server thread/WARN] [minecraft/DedicatedServer]: To change this, set "online-mode" to "true" in the server.properties file.
[15:25:55] [Server thread/INFO] [FML]: Applying holder lookups
[15:25:55] [Server thread/INFO] [FML]: Holder lookups applied
[15:25:55] [Server thread/INFO] [FML]: Injecting itemstacks
[15:25:55] [Server thread/INFO] [FML]: Itemstack injection complete
[15:25:55] [Server thread/INFO] [FML]: Forge Mod Loader has successfully loaded 4 mods
[15:25:55] [Server thread/INFO] [minecraft/DedicatedServer]: Preparing level "world"
[15:25:56] [Server thread/INFO] [FML]: Loading dimension 0 (world) (net.minecraft.server.dedicated.DedicatedServer@5281f20d)
[15:25:56] [Forge Version Check/INFO] [forge.VersionCheck]: [forge] Found status: OUTDATED Target: 14.23.5.2847
[15:25:56] [Server thread/INFO] [minecraft/AdvancementList]: Loaded 488 advancements
[15:25:56] [Server thread/INFO] [FML]: Loading dimension -1 (world) (net.minecraft.server.dedicated.DedicatedServer@5281f20d)
[15:25:56] [Server thread/INFO] [FML]: Loading dimension 1 (world) (net.minecraft.server.dedicated.DedicatedServer@5281f20d)
[15:25:56] [Server thread/INFO] [minecraft/MinecraftServer]: Preparing start region for level 0
[15:25:58] [Server thread/INFO] [minecraft/MinecraftServer]: Preparing spawn area: 0%
[15:25:59] [Server thread/INFO] [minecraft/MinecraftServer]: Preparing spawn area: 22%
[15:26:00] [Server thread/INFO] [minecraft/MinecraftServer]: Preparing spawn area: 62%
[15:26:01] [Server thread/INFO] [minecraft/DedicatedServer]: Done (5.338s)! For help, type "help" or "?"
[15:26:01] [Server thread/INFO] [FML]: Unloading dimension -1
[15:26:01] [Server thread/INFO] [FML]: Unloading dimension 1
[15:26:27] [Server thread/INFO] [FML]: Connection received without FML marker, assuming vanilla.
[15:26:27] [Server thread/INFO] [FML]: Opening channel which already seems to have a state set. This is a vanilla connection. Handshake handler will stop now
[15:26:27] [Server thread/INFO] [FML]: [Server thread] Server side vanilla connection established
[15:26:27] [Server thread/INFO] [minecraft/PlayerList]: 开发咕[/116.116.253.64:19073] logged in with entity id 334 at (317.5385544161457, 89.3873414859215, 109.05768667139483)
[15:26:27] [Server thread/INFO] [minecraft/DedicatedServer]: 开发咕 joined the game
[15:27:10] [Server thread/INFO] [minecraft/NetHandlerPlayServer]: 开发咕 lost connection: Internal Exception: io.netty.channel.unix.Errors$NativeIoException: syscall:read(..) failed: Connection reset by peer
[15:27:10] [Server thread/INFO] [minecraft/DedicatedServer]: 开发咕 left the game
>
（说明：开发咕为我的账号，因为机器运存小，所以设置了很小的启动内存，如果需要更多，请帮助我设定一个合理的数值）

再就没有严重错误了啊
中间连着四个WARN是因为你没有开正版验证。。
有一个提示是建议你调大一点内存，但是不调也行
具体得分配多少，得看你玩起来卡不卡
tps经常拉闸就多分一点，还好就不用分

知道了，谢谢，我已经设置为512-1240了

话说最近阿里云不是能白嫖 2核4G的vps吗

我没找到诶，我用的114一年的学生机