Umm, I started a test mod and it crashes ery time  :'(

Exception in thread "main" [15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: java.lang.reflect.InvocationTargetException
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at java.lang.reflect.Method.invoke(Unknown Source)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at net.minecraftforge.gradle.GradleStartCommon.launch(GradleStartCommon.java:97)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at GradleStart.main(GradleStart.java:26)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: Caused by: java.lang.NoSuchMethodError: com.google.common.base.Objects.firstNonNull(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at com.google.common.cache.CacheBuilder.getKeyStrength(CacheBuilder.java:529)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at com.google.common.cache.LocalCache.<init>(LocalCache.java:242)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at com.google.common.cache.LocalCache$LocalLoadingCache.<init>(LocalCache.java:4814)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at com.google.common.cache.CacheBuilder.build(CacheBuilder.java:789)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at net.minecraftforge.fml.common.asm.ASMTransformerWrapper.<clinit>(ASMTransformerWrapper.java:39)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at net.minecraftforge.fml.relauncher.CoreModManager$FMLPluginWrapper.injectIntoClassLoader(CoreModManager.java:124)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at net.minecraft.launchwrapper.Launch.launch(Launch.java:115)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
[15:45:04] [main/INFO] [sTDERR]: [java.lang.ThreadGroup:uncaughtException:-1]: 	... 6 more

Any help?

Can you give us a little bit more? What do you mean by test mod? Do you mean the example mod that comes with forge on setup? If not provide the code to the class. A like saying it crashes then a crash log does not help much unless we know whats going on.....

I have a 'good' mod that I am working on where my entity isn't working very well.  I created a new project to test out new ways of trying to do things, possibly finding ways to solve things in my main mod. However, whenever I try to run it, this happens. It says there is an error in the project, but doesn't tell me whatsoever. It's not in any of the classes i'm pretty sure.

Those java line numbers in the crash report are clickable. Get in there, set breakpoints, run in the debugger, and see what's what. Report back with more context, including all source code of any mod class referenced in the broken reflection code.

 

If your mod classes are not involved at all, then you have an environment setup issue (like mixing versions, dropping a core mod into the workspace's mods folder etc). In that case, clean up. If you can't repair your existing workspace, then try setting up a fresh decomp workspace/ gradle Eclipse from scratch.

 

BTW, What core mods and other infernal complications have you mixed in here without telling us?

Fixed - Created New Workspace and all works fine.