So I downloaded latest 1.7.2 Forge build (1.7.2.10.12.2.1161) yesterday, installed the server aaaaaand this:
[mr@server 172-server-1]$ java -jar forge-1.7.2-10.12.2.1161-mc172-universal.jar
[08:00:29] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLServerTweaker
[08:00:29] [main/INFO] [LaunchWrapper]: Using primary tweak class name cpw.mods.fml.common.launcher.FMLServerTweaker
[08:00:29] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLServerTweaker
[08:00:29] [main/INFO] [FML]: Forge Mod Loader version 7.2.217.1161 for Minecraft 1.7.2 loading
[08:00:30] [main/INFO] [FML]: Java is Java HotSpot(TM) 64-Bit Server VM, version 1.9.0-ea, running on Linux:amd64:3.15.1-1-ARCH, installed at /home/mr/bin/jdk1.9.0/jre
[08:00:30] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[08:00:30] [main/INFO] [LaunchWrapper]: Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker
[08:00:30] [main/INFO] [LaunchWrapper]: Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
[08:00:30] [main/ERROR] [LaunchWrapper]: Unable to launch
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:913) ~[?:1.9.0-ea]
at java.util.ArrayList$Itr.remove(ArrayList.java:877) ~[?:1.9.0-ea]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:117) [launchwrapper-1.9.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.9.0-ea]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.9.0-ea]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.9.0-ea]
at java.lang.reflect.Method.invoke(Method.java:484) ~[?:1.9.0-ea]
at cpw.mods.fml.relauncher.ServerLaunchWrapper.run(ServerLaunchWrapper.java:43) [forge-1.7.2-10.12.2.1161-mc172-universal.jar:?]
at cpw.mods.fml.relauncher.ServerLaunchWrapper.main(ServerLaunchWrapper.java:12) [forge-1.7.2-10.12.2.1161-mc172-universal.jar:?]
[mr@server 172-server-1]$
OS: Arch Linux kernel 3.15.1-1
Java: 1.9.0-ea
Please help!
EDIT: NO mods.