[21:19:32] [DEBUG] Benchmark.logBenchAs:73: UnreadNews Init took 26 ms.
[21:21:01] [INFO] LaunchFrame.doLogin:437: Logging in...
[21:21:01] [DEBUG] AuthlibHelper.authenticateWithAuthlib:63: Username given Not 100% sure, mojangdata might contain different username
[21:21:01] [INFO] AuthlibHelper.authenticateWithAuthlib:64: Beginning authlib authentication attempt
[21:21:01] [INFO] AuthlibHelper.authenticateWithAuthlib:65: successfully created YggdrasilAuthenticationService
[21:21:01] [DEBUG] AuthlibHelper.authenticateWithAuthlib:72: mojangData was passed to current method
[21:21:01] [DEBUG] AuthlibHelper.authenticateWithAuthlib:75: Loading mojangData into authlib
[21:21:02] [DEBUG] AuthlibHelper.authenticateWithAuthlib:133: Authentication is valid
[21:21:02] [DEBUG] AuthlibHelper.authenticateWithAuthlib:136: loggedIn() && CanPlayOnline()
[21:21:02] [DEBUG] AuthlibHelper.authenticateWithAuthlib:140: Authentication done, returning LoginResponse
[21:21:02] [DEBUG] Benchmark.logBenchAs:73: Login Worker Run took 782 ms.
[21:21:02] [DEBUG] LaunchFrame$14.done:479: responseStr: good
[21:21:02] [INFO] LaunchFrame$14.done:482: Login complete.
[21:21:02] [DEBUG] User.writeObject:185: starting...
[21:21:02] [DEBUG] LaunchFrame$14.done:486: user data saved
[21:21:02] [DEBUG] LaunchFrame.runGameUpdater:530: ForceUpdate: false
[21:21:02] [DEBUG] LaunchFrame.runGameUpdater:531: installPath: C:\Users\Sam\Downloads
[21:21:02] [DEBUG] LaunchFrame.runGameUpdater:532: pack dir: BlastOff
[21:21:02] [DEBUG] LaunchFrame.runGameUpdater:533: pack check path: BlastOff\version
[21:21:02] [INFO] MCInstaller.gatherAssets:127: Checking local assets file, for MC version1.7.10 Please wait!
[21:21:02] [DEBUG] MCInstaller.gatherAssets:132: Checking pack libraries
[21:21:02] [DEBUG] MCInstaller.gatherAssets:184: Checking minecraft version json
[21:21:02] [DEBUG] MCInstaller.gatherAssets:199: checking minecraft libraries
[21:21:02] [DEBUG] MCInstaller.gatherAssets:267: Checking minecraft assets
[21:21:04] [DEBUG] MCInstaller.gatherAssets:281: Starting TaskHandler to check MC assets
[21:21:04] [DEBUG] Benchmark.logBenchAs:73: parallel asset check took 428 ms.
[21:21:04] [INFO] MCInstaller.launchMinecraft:328: Setting up native libraries for Blast Off! v Recommended Version MC 1.7.10
[21:21:04] [DEBUG] MCInstaller.launchMinecraft:355: packbaseJSON 1.7.10
[21:21:05] [INFO] MCLauncher.syncAssets:271: Syncing Assets:
[21:21:05] [INFO] MCLauncher.launchMinecraft:76: Java Path: C:\Program Files\Java\jre1.8.0_25\bin\javaw.exe
[21:21:05] [INFO] MCLauncher.launchMinecraft:77: Pack: Blast Off! 1.7.10
[21:21:05] [INFO] MCLauncher.setMemory:254: Setting MinMemory to 256
[21:21:05] [INFO] MCLauncher.setMemory:256: Setting MaxMemory to 4096
[21:21:05] [INFO] MCLauncher.launchMinecraft:99: Defaulting PermSize to 256m
[21:21:05] [main/INFO]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[21:21:05] [main/ERROR]: Unable to launch
java.lang.ClassNotFoundException: cpw.mods.fml.common.launcher.FMLTweaker
at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.8.0_25]
at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.8.0_25]
at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_25]
at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.8.0_25]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_25]
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[?:1.8.0_25]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_25]
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:106) ~[launchwrapper-1.11.jar:?]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_25]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_25]
at java.lang.Class.forName0(Native Method) ~[?:1.8.0_25]
at java.lang.Class.forName(Unknown Source) ~[?:1.8.0_25]
at net.minecraft.launchwrapper.Launch.launch(Launch.java:98) [launchwrapper-1.11.jar:?]
at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.11.jar:?]
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=256m; support was removed in 8.0
[21:21:06] [DEBUG] Benchmark.logBenchAs:73: UnreadNews Init took 5 ms.
[21:23:37] Logs copied to clipboard
So I have been getting this when I tried to load up the pack for the first time, any suggestions as to what's gone wrong?