Bug Java 8 not compatible with 1.7.10 packs???

[Spudman_98]

PC Specs:
Intel P8700 Dual core @ 2.53Ghz
8GB DDR3 (2x4GB SODIMM)
ATI HD 3670
Windows 10 Pro
Java (latest version "period")

Modpack: (any that falls under "1.7.10")
Issue: spits out log-

[21:04:33] [main/INFO]: Loading tweak class name cpw.mods.fml.common.launcher.FMLTweaker
[21:04:33] [main/ERROR]: Unable to launch
java.lang.ClassNotFoundException: cpw.mods.fml.common.launcher.FMLTweaker
at java.net.URLClassLoader$1.run(URLClassLoader.java:372) ~[?:1.8.0_25]
at java.net.URLClassLoader$1.run(URLClassLoader.java:361) ~[?:1.8.0_25]
at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_25]
at java.net.URLClassLoader.findClass(URLClassLoader.java:360) ~[?:1.8.0_25]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_25]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) ~[?:1.8.0_25]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_25]
at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:106) ~[launchwrapper-1.12.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_25]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_25]
at java.lang.Class.forName0(Native Method) ~[?:1.8.0_25]
at java.lang.Class.forName(Class.java:344) ~[?:1.8.0_25]
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:?]
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=256m; support was removed in 8.0



Ive noticed that FTB has changed to launching from curse... not an issue... but Ive spent at least 2 days trying to trouble shoot why the modpacks arent launching.

my suspicion is forge as if I was to load just a normal release of MC 1.7.10 it works fine. Google has been no help what so ever, I have downgraded to Java 7, then forcing the launcher to open with that version and still same error is being output. I have also tried to change the destination in which Java is executed from (Java 7, in contrast to the curse launchers own in the files...)

Any help that will lead to the solution will be much appreciated <3
PS ( not too sure if this is the right area to post this hahaha)

 

[Henry Link]

I'm not sure what your issue is but it isn't java. I can launch Infinity using the latest java (8-101) using the legacy launcher just fine. Also, the curse launcher uses java 8-25. My guess would be your AV software might be blocking it. Try to put in file exceptions for you FTB directories into it.

 

[Spudman_98]

I'm not sure what your issue is but it isn't java. I can launch Infinity using the latest java (8-101) using the legacy launcher just fine. Also, the curse launcher uses java 8-25. My guess would be your AV software might be blocking it. Try to put in file exceptions for you FTB directories into it.

Tried allowing both Curse launcher and javaw.exe past the firewall, still no progress... Maybe I should try different launcher other than Curse?

 

[Henry Link]

The legacy FTB launcher is still available. Just go to the main FTB website and look for the legacy links just under the download button.

 

[UniZero]

https://gist.github.com/jikuja/7e0828dca7d264e850be306b58893127