As the title says, I installed a fresh profile with Forge on 1.12.2 (without any mods yet so I could check if it works) and when I go to launch it, it crashes. I disabled the splash-screen in the .minecraft/configs folder but the problem still persists. Here's what latest.log has to say.
 

Spoiler

[18:36:13] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[18:36:13] [main/INFO]: Using primary tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[18:36:13] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLTweaker
[18:36:13] [main/INFO]: Forge Mod Loader version 14.23.1.2558 for Minecraft 1.12.2 loading
[18:36:13] [main/INFO]: Java is Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_25, running on Windows 10:amd64:10.0, installed at C:\Curse\Minecraft\Install\runtime\jre-x64\1.8.0_25
[18:36:13] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[18:36:13] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLDeobfTweaker
[18:36:13] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[18:36:13] [main/INFO]: Calling tweak class net.minecraftforge.fml.common.launcher.FMLInjectionAndSortingTweaker
[18:36:13] [main/INFO]: Calling tweak class net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper
[18:36:17] [main/FATAL]: Patcher expecting non-empty class data file for net.minecraft.crash.CrashReport$1, but received empty.
[18:36:17] [main/ERROR]: Unable to launch
java.lang.RuntimeException: java.lang.RuntimeException: Patcher expecting non-empty class data file for net.minecraft.crash.CrashReport$1, but received empty, your vanilla jar may be corrupt.
    at net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper.injectIntoClassLoader(CoreModManager.java:170) ~[forge-1.12.2-14.23.1.2558.jar:?]
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:115) [launchwrapper-1.12.jar:?]
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
Caused by: java.lang.RuntimeException: Patcher expecting non-empty class data file for net.minecraft.crash.CrashReport$1, but received empty, your vanilla jar may be corrupt.
    at net.minecraftforge.fml.common.patcher.ClassPatchManager.applyPatch(ClassPatchManager.java:112) ~[forge-1.12.2-14.23.1.2558.jar:?]
    at net.minecraftforge.fml.common.patcher.ClassPatchManager.getPatchedResource(ClassPatchManager.java:75) ~[forge-1.12.2-14.23.1.2558.jar:?]
    at net.minecraftforge.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.getFieldType(FMLDeobfuscatingRemapper.java:219) ~[forge-1.12.2-14.23.1.2558.jar:?]
    at net.minecraftforge.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.parseField(FMLDeobfuscatingRemapper.java:192) ~[forge-1.12.2-14.23.1.2558.jar:?]
    at net.minecraftforge.fml.common.asm.transformers.deobf.FMLDeobfuscatingRemapper.setup(FMLDeobfuscatingRemapper.java:161) ~[forge-1.12.2-14.23.1.2558.jar:?]
    at net.minecraftforge.fml.common.asm.FMLSanityChecker.injectData(FMLSanityChecker.java:188) ~[forge-1.12.2-14.23.1.2558.jar:?]
    at net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper.injectIntoClassLoader(CoreModManager.java:165) ~[forge-1.12.2-14.23.1.2558.jar:?]
    ... 2 more
[18:36:17] [main/INFO]: [java.lang.ThreadGroup:uncaughtException:1052]: net.minecraftforge.fml.relauncher.FMLSecurityManager$ExitTrappedException
[18:36:17] [main/INFO]: [java.lang.ThreadGroup:uncaughtException:1052]:     at net.minecraftforge.fml.relauncher.FMLSecurityManager.checkPermission(FMLSecurityManager.java:49)
[18:36:17] [main/INFO]: [java.lang.ThreadGroup:uncaughtException:1052]:     at java.lang.SecurityManager.checkExit(SecurityManager.java:761)
[18:36:17] [main/INFO]: [java.lang.ThreadGroup:uncaughtException:1052]:     at java.lang.Runtime.exit(Runtime.java:107)
[18:36:17] [main/INFO]: [java.lang.ThreadGroup:uncaughtException:1052]:     at java.lang.System.exit(System.java:968)
[18:36:17] [main/INFO]: [java.lang.ThreadGroup:uncaughtException:1052]:     at net.minecraft.launchwrapper.Launch.launch(Launch.java:138)
[18:36:17] [main/INFO]: [java.lang.ThreadGroup:uncaughtException:1052]:     at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
 

Could anyone help me with this?
 

Have you tried deleting and re-creating the profile so it redownloads minecraft? If not I'd give that a try