Bug FTB Revelation Failed To Launch

[PandamoniumFTB]

I am attempting to launch FTB Revelation after a fresh install, and the game doesn't open, and it comes back with this error message.

[12:34:09] [main/ERROR]: Unable to launch
java.lang.ClassNotFoundException: net.minecraftforge.fml.common.launcher.FMLTweaker

at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.8.0_231]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_231]
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[?:1.8.0_231]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_231]
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:106) ~​

[launchwrapper-1.12.jar:?]

at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_231]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_231]
at java.lang.Class.forName0(Native Method) ~[?:1.8.0_231]
at java.lang.Class.forName(Unknown Source) ~[?:1.8.0_231]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:98) [launchwrapper-1.12.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]​

I'm not exactly the most well-versed when it comes to Java, so any help to fix this would be appreciated, thanks!