When attempting to install Forge on a clean installation of Minecraft, the Forge launcher displays an error message saying that it can't run the FMLCorePlugin.  I get the following report in my Forge log.

 

 

2013-05-02 15:54:53 [iNFO] [ForgeModLoader] Forge Mod Loader version 5.2.2.684 for Minecraft 1.5.2 loading

2013-05-02 15:54:53 [iNFO] [ForgeModLoader] Java is Java HotSpot Client VM, version 1.7.0_21, running on Windows 7:x86:6.1, installed at c:\program files (x86)\java\jre7

2013-05-02 15:54:53 [FINE] [ForgeModLoader] Java classpath at launch is C:\Users\Zachary\AppData\Local\Temp\e4jE9FA.tmp_dir\exe4jlib.jar;C:\Users\Zachary\AppData\Local\Temp\e4jE9FA.tmp_dir\MinecraftSP.jar;

2013-05-02 15:54:53 [FINE] [ForgeModLoader] Java library path at launch is C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Program Files\Dell\DW WLAN Card;C:\Program Files (x86)\Common Files\Roxio Shared\DLLShared\;C:\Program Files\WIDCOMM\Bluetooth Software\;C:\Program Files\WIDCOMM\Bluetooth Software\syswow64;C:\Program Files (x86)\Windows Live\Shared;C:\Program Files (x86)\Common Files\HP\Digital Imaging\bin;C:\Program Files (x86)\HP\Digital Imaging\bin\;C:\Program Files (x86)\HP\Digital Imaging\bin\Qt\Qt 4.3.3;C:\Program Files\Microsoft Windows Performance Toolkit\;C:\Program Files (x86)\OpenLibraries\bin;%PROGRAMFILES%\Internet Explorer;C:\Program Files (x86)\QuickTime\QTSystem\;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\IVI Foundation\VISA\WinNT\Bin\;C:\Program Files\IVI Foundation\VISA\Win64\Bin\;C:\Program Files (x86)\IVI Foundation\VISA\WinNT\Bin;C:\Windows\System32\WindowsPowerShell\v1.0\;c:\program files (x86)\java\jre7\bin

2013-05-02 15:54:53 [FINE] [ForgeModLoader] Enabling runtime deobfuscation

2013-05-02 15:54:53 [FINEST] [ForgeModLoader] All core mods are successfully located

2013-05-02 15:54:53 [FINEST] [ForgeModLoader] Discovering coremods

2013-05-02 15:54:53 [FINEST] [ForgeModLoader] Found library file argo-small-3.2.jar present and correct in lib dir

2013-05-02 15:54:53 [FINEST] [ForgeModLoader] Found library file guava-14.0-rc3.jar present and correct in lib dir

2013-05-02 15:54:53 [FINEST] [ForgeModLoader] Found library file asm-all-4.1.jar present and correct in lib dir

2013-05-02 15:54:53 [FINEST] [ForgeModLoader] Found library file bcprov-jdk15on-148.jar present and correct in lib dir

2013-05-02 15:54:53 [FINEST] [ForgeModLoader] Downloading file http://files.minecraftforge.net/fmllibs/deobfuscation_data_1.5.2.zip

2013-05-02 15:54:53 [iNFO] [ForgeModLoader] Downloading file http://files.minecraftforge.net/fmllibs/deobfuscation_data_1.5.2.zip

2013-05-02 15:54:59 [FINEST] [ForgeModLoader] Download complete

2013-05-02 15:54:59 [iNFO] [ForgeModLoader] Download complete

2013-05-02 15:54:59 [FINEST] [ForgeModLoader] Library file deobfuscation_data_1.5.2.zip was downloaded and verified successfully

2013-05-02 15:54:59 [FINEST] [ForgeModLoader] Downloading file http://files.minecraftforge.net/fmllibs/scala-library.jar

2013-05-02 15:54:59 [iNFO] [ForgeModLoader] Downloading file http://files.minecraftforge.net/fmllibs/scala-library.jar

2013-05-02 15:55:10 [FINEST] [ForgeModLoader] Download complete

2013-05-02 15:55:10 [iNFO] [ForgeModLoader] Download complete

2013-05-02 15:55:10 [FINEST] [ForgeModLoader] Library file scala-library.jar was downloaded and verified successfully

2013-05-02 15:55:10 [FINEST] [ForgeModLoader] Running coremod plugins

2013-05-02 15:55:10 [FINEST] [ForgeModLoader] Running coremod plugin FMLCorePlugin

2013-05-02 15:55:10 [sEVERE] [ForgeModLoader] An error occurred loading the deobfuscation map data

java.io.FileNotFoundException: C:\Users\Zachary\AppData\Roaming\.minecraft\lib\deobfuscation_data_1.5.2.zip (The system cannot find the file specified)

at java.util.zip.ZipFile.open(Native Method)

at java.util.zip.ZipFile.<init>(Unknown Source)

at java.util.zip.ZipFile.<init>(Unknown Source)

at java.util.zip.ZipFile.<init>(Unknown Source)

at cpw.mods.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.setup(FMLDeobfuscatingRemapper.java:84)

at cpw.mods.fml.common.asm.FMLSanityChecker.injectData(FMLSanityChecker.java:141)

at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:301)

at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:172)

at cpw.mods.fml.relauncher.FMLRelauncher.relaunchApplet(FMLRelauncher.java:259)

at cpw.mods.fml.relauncher.FMLRelauncher.appletEntry(FMLRelauncher.java:229)

at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:25)

at net.minecraft.Launcher.replace(Launcher.java:153)

at net.minecraft.Launcher$1.run(Launcher.java:94)

2013-05-02 15:55:18 [iNFO] [sTDERR] Exception in thread "Thread-3" java.lang.RuntimeException: java.lang.RuntimeException: java.lang.NullPointerException

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:192)

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.relaunchApplet(FMLRelauncher.java:259)

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.appletEntry(FMLRelauncher.java:229)

2013-05-02 15:55:18 [iNFO] [sTDERR] at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:25)

2013-05-02 15:55:18 [iNFO] [sTDERR] at net.minecraft.Launcher.replace(Launcher.java:153)

2013-05-02 15:55:18 [iNFO] [sTDERR] at net.minecraft.Launcher$1.run(Launcher.java:94)

2013-05-02 15:55:18 [iNFO] [sTDERR] Caused by: java.lang.RuntimeException: java.lang.NullPointerException

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:306)

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:172)

2013-05-02 15:55:18 [iNFO] [sTDERR] ... 5 more

2013-05-02 15:55:18 [iNFO] [sTDERR] Caused by: java.lang.NullPointerException

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.setup(FMLDeobfuscatingRemapper.java:125)

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.common.asm.FMLSanityChecker.injectData(FMLSanityChecker.java:141)

2013-05-02 15:55:18 [iNFO] [sTDERR] at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:301)

2013-05-02 15:55:18 [iNFO] [sTDERR] ... 6 more

 

 

 

I had the same issue until I tried this.  Now it works perfectly.

I had the same issue until I tried this.  Now it works perfectly.

 

Tried what?