This is the stack trace I got and I was wondering how I fix this, it doesn't seem to be about my code, it says a file is missing  but I don't know what it is. Is 1.7.10 unstable?

 

[11:09:32] [main/INFO] [GradleStart]: No arguments specified, assuming client.
[11:09:32] [main/INFO] [GradleStart]: Extra: []
Exception in thread "main" java.lang.RuntimeException: java.io.FileNotFoundException: C:\Users\[userName]\.gradle\caches\minecraft\assets\indexes\{ASSET_INDEX}.json (The system cannot find the file specified)
at com.google.common.base.Throwables.propagate(Throwables.java:160)
at GradleStart.setupAssets(GradleStart.java:260)
at GradleStart.startClient(GradleStart.java:82)
at GradleStart.main(GradleStart.java:56)
Caused by: java.io.FileNotFoundException: C:\Users\[userName]\.gradle\caches\minecraft\assets\indexes\{ASSET_INDEX}.json (The system cannot find the file specified)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at java.io.FileReader.<init>(Unknown Source)
at GradleStart.loadAssetsIndex(GradleStart.java:266)
at GradleStart.setupAssets(GradleStart.java:204)
... 2 more
Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release

It is looking for your Minecraft assets folder, which Gradle should set up for you automatically. Open the folder it specifies and see if you have both an 'indexes' and 'objects' folder; if you do, try restarting your IDE, sometimes that's all it needs; if not, try running 'gradlew --refresh-dependencies setupDecompWorkspace' again.

I did the last method and now it is working... THANK YOU VERY MUCH!