I am having a similar issue and I am running 64 bit java and have replaced some files but this is the error I am getting:
C:UsersMattDesktopGamesBig Dig Server>java -Xmx3G -Xms2G -jar BigDig.jar no
gui
2013-12-29 16:35:32 [iNFO] [ForgeModLoader] Forge Mod Loader version 5.2.12.712
for Minecraft 1.5.2 loading
2013-12-29 16:35:32 [iNFO] [ForgeModLoader] Java is Java HotSpot 64-Bit Serv
er VM, version 1.7.0_45, running on Windows 7:amd64:6.1, installed at C:Program
FilesJavajre7
2013-12-29 16:35:32 [WARNING] [ForgeModLoader] The coremod bspkrs.treecapitator.
fml.asm.TreeCapitatorCorePlugin does not have a MCVersion annotation, it may cau
se issues with this version of Minecraft
2013-12-29 16:35:32 [WARNING] [ForgeModLoader] The coremod codechicken.core.asm.
CodeChickenCorePlugin does not have a MCVersion annotation, it may cause issues
with this version of Minecraft
2013-12-29 16:35:32 [WARNING] [ForgeModLoader] The coremod cofh.asm.CoFHPlugin d
oes not have a MCVersion annotation, it may cause issues with this version of Mi
necraft
2013-12-29 16:35:32 [WARNING] [ForgeModLoader] The coremod micdoodle8.mods.galac
ticraft.asm.GalacticraftPlugin does not have a MCVersion annotation, it may caus
e issues with this version of Minecraft
2013-12-29 16:35:32 [WARNING] [ForgeModLoader] The coremod mods.immibis.microblo
cks.coremod.MicroblocksCoreMod does not have a MCVersion annotation, it may caus
e issues with this version of Minecraft
2013-12-29 16:35:32 [WARNING] [ForgeModLoader] The coremod codechicken.nei.asm.N
EICorePlugin does not have a MCVersion annotation, it may cause issues with this
version of Minecraft
2013-12-29 16:35:32 [iNFO] [ForgeModLoader] Downloading file http://files.minecr
aftforge.net/fmllibs/argo-small-3.2.jar
2013-12-29 16:35:33 [iNFO] [ForgeModLoader] Download complete
2013-12-29 16:35:33 [iNFO] [ForgeModLoader] Downloading file http://files.minecr
aftforge.net/fmllibs/guava-14.0-rc3.jar
2013-12-29 16:35:36 [iNFO] [ForgeModLoader] Download complete
2013-12-29 16:35:36 [iNFO] [ForgeModLoader] Downloading file http://files.minecr
aftforge.net/fmllibs/asm-all-4.1.jar
2013-12-29 16:35:37 [iNFO] [ForgeModLoader] Download complete
2013-12-29 16:35:37 [iNFO] [ForgeModLoader] Downloading file http://files.minecr
aftforge.net/fmllibs/bcprov-jdk15on-148.jar
2013-12-29 16:35:37 [sEVERE] [ForgeModLoader] There was a problem downloading th
e file bcprov-jdk15on-148.jar automatically. Perhaps you have an environment wit
hout internet access. You will need to download the file manually or restart and
let it try again
2013-12-29 16:35:37 [iNFO] [ForgeModLoader] Downloading file http://files.minecr
aftforge.net/fmllibs/deobfuscation_data_1.5.2.zip
2013-12-29 16:35:38 [iNFO] [ForgeModLoader] Download complete
2013-12-29 16:35:38 [iNFO] [ForgeModLoader] Downloading file http://files.minecr
aftforge.net/fmllibs/scala-library.jar
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] There was a problem downloading th
e file scala-library.jar automatically. Perhaps you have an environment without
internet access. You will need to download the file manually or restart and let
it try again
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] There were errors during initial F
ML setup. Some files failed to download or were otherwise corrupted. You will ne
ed to manually obtain the following files from these download links and ensure y
our lib directory is clean.
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] *** Download http://files.minecraf
tforge.net/fmllibs/argo-small-3.2.jar
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] *** Download http://files.minecraf
tforge.net/fmllibs/guava-14.0-rc3.jar
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] *** Download http://files.minecraf
tforge.net/fmllibs/asm-all-4.1.jar
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] *** Download http://files.minecraf
tforge.net/fmllibs/bcprov-jdk15on-148.jar
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] *** Download http://files.minecraf
tforge.net/fmllibs/deobfuscation_data_1.5.2.zip
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] *** Download http://files.minecraf
tforge.net/fmllibs/scala-library.jar
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] <===========>
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] The following is the errors that c
aused the setup to fail. They may help you diagnose and resolve the issue
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] A download error occured
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] A download error occured
2013-12-29 16:35:38 [sEVERE] [ForgeModLoader] <<< ==== >>>
C:UsersMattDesktopGamesBig Dig Server>pause
Press any key to continue . . .
Can anyone help me with this as I really want to run my own Big Dig server