I'm having some major difficulties with forge right now, and especially my java as well, I currently ONLY have java 8u20 and Java SE development kit 8u20, if I'm missing a java, please let me know. Currently what happens is I will launch a minecraft forge 1.7.10 10.13.0.1208 and nothing... Launcher disappears and not even an attempt to launch minecraft forge occurs. I've tried many different solutions, checked many different threads, and the results are the same, well, at least now I can start up the launcher... Additionally, if this is any useful information, the same thing happens with my forge servers, double click, not even an attempt.. Any help is greatly appreciated. Thanks
Thanks Balthasar, but I did that, only java 8 works with my minecraft, when I downgrade to java 7 I get prompted when launching minecraft with "java runtime environment does not exist or is corrupt" something to that extent, perhaps downgrading is still an option, but what would I need to make up for the missing JRE? I've tried installing that seperately as well, that only reinstalled Java 7
You should see my downloads history, it's cluttered with various versions of Java... If I tried installing java 7 one more time, I'm afraid I'd be classified as clinically insane cx
oh yes that fun stuff I encountered that issue myself what you need to do is copy the contents of the java 7 folder and paste them into the java 8 folder.
Then, press Win-R and type cmd. It will open Windows Console. Type java -version. If it prints Java version, you can skip the following paragraph.
if it prints that command not found, run the PATH=%PATH%;C:\Program Files (x86)\Java\jre7\bin. Don't forget about the semicolon after %PATH%, it is important! Then run java -version again. It should print Java version, if you installed Java correctly (and to the standard path: C:\Program Files (x86)\Java\jre7).
Now try to install Forge (verify that you have the correct version: if you downloaded Forge for 1.7.10 and you have Minecraft 1.6.4, it mustn't work) and run Minecraft.
Haha, ironically I needed to reinstall my entire windows 8! I'm sure there was a simpler way to do it, but this has been solved! Thanks for the input, I'm sure it'd be very useful (and a LOT more effecient for others who are experiencing my troubles) but I had my friend reinstall and completely optimize my computer/win8 for best performance and organization, as I am an OCD freak.
What's funny is i'm having the exact same issue and going to end up doing the same thing. Guess there isn't no work around. Least I know from your experience that re-installing windows 8 is the only option that works.
sorry for the necro but there IS 1 workaround. its quite simple: install java 7 as normal, leaving java 8, then go to your minecrafts profile button in the launcher and check the "executable" button and change the path so it goes to the java 7 version of 'javaw.exe". it works. i just did it myself.
You should see my downloads history, it's cluttered with various versions of Java... If I tried installing java 7 one more time, I'm afraid I'd be classified as clinically insane cx
2014-08-21 23:51:59 [INFO] [ForgeModLoader] Forge Mod Loader version 6.4.49.965 for Minecraft 1.6.4 loading
2014-08-21 23:51:59 [INFO] [ForgeModLoader] Java is Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_20, running on Windows 8.1:amd64:6.3, installed at C:\Program Files\Java\jre1.8.0_20
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Java classpath at launch is C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\net\minecraftforge\minecraftforge\9.11.1.965\minecraftforge-9.11.1.965.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\net\minecraft\launchwrapper\1.8\launchwrapper-1.8.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\org\ow2\asm\asm-all\4.1\asm-all-4.1.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-library\2.10.2\scala-library-2.10.2.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\org\scala-lang\scala-compiler\2.10.2\scala-compiler-2.10.2.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\lzma\lzma\0.0.1\lzma-0.0.1.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.5\jopt-simple-4.5.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\com\paulscode\codecjorbis\20101023\codecjorbis-20101023.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\com\paulscode\codecwav\20101023\codecwav-20101023.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\com\paulscode\libraryjavasound\20101123\libraryjavasound-20101123.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\com\paulscode\librarylwjglopenal\20100824\librarylwjglopenal-20100824.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\com\paulscode\soundsystem\20120107\soundsystem-20120107.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\argo\argo\2.25_fixed\argo-2.25_fixed.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\org\bouncycastle\bcprov-jdk15on\1.47\bcprov-jdk15on-1.47.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\com\google\guava\guava\14.0\guava-14.0.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\org\apache\commons\commons-lang3\3.1\commons-lang3-3.1.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\commons-io\commons-io\2.4\commons-io-2.4.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\net\java\jutils\jutils\1.0.0\jutils-1.0.0.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\com\google\code\gson\gson\2.2.2\gson-2.2.2.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl\2.9.0\lwjgl-2.9.0.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\lwjgl_util\2.9.0\lwjgl_util-2.9.0.jar;C:\Users\Alexander\AppData\Roaming\.minecraft\versions\1.6.4-Forge9.11.1.965\1.6.4-Forge9.11.1.965.jar
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Java library path at launch is C:\Users\Alexander\AppData\Roaming\.minecraft\versions\1.6.4-Forge9.11.1.965\1.6.4-Forge9.11.1.965-natives-1004542169605
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Enabling runtime deobfuscation
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Instantiating coremod class FMLCorePlugin
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Enqueued coremod FMLCorePlugin
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Instantiating coremod class FMLForgePlugin
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Enqueued coremod FMLForgePlugin
2014-08-21 23:51:59 [FINE] [ForgeModLoader] All fundamental core mods are successfully located
2014-08-21 23:51:59 [FINE] [ForgeModLoader] Discovering coremods
2014-08-21 23:51:59 [INFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
2014-08-21 23:51:59 [INFO] [ForgeModLoader] Loading tweak class name cpw.mods.fml.common.launcher.FMLDeobfTweaker
2014-08-21 23:51:59 [INFO] [ForgeModLoader] Calling tweak class cpw.mods.fml.common.launcher.FMLInjectionAndSortingTweaker
2014-08-21 23:51:59 [SEVERE] [ForgeModLoader] Unable to launch
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(Unknown Source)
at java.util.ArrayList$Itr.remove(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:114)
at net.minecraft.launchwrapper.Launch.main(Launch.java:27)
Then, press Win-R and type cmd. It will open Windows Console. Type java -version. If it prints Java version, you can skip the following paragraph.
if it prints that command not found, run the PATH=%PATH%;C:\Program Files (x86)\Java\jre7\bin. Don't forget about the semicolon after %PATH%, it is important! Then run java -version again. It should print Java version, if you installed Java correctly (and to the standard path: C:\Program Files (x86)\Java\jre7).
Now try to install Forge (verify that you have the correct version: if you downloaded Forge for 1.7.10 and you have Minecraft 1.6.4, it mustn't work) and run Minecraft.