WoodSphinx

Hey there! This is my first time posting, sorry if this in the wrong place or in the wrong format. I've installed Java 8 JDK, IntelliJ IDEA and the Forge MDK, and I have the latest version of 64-bit Java. I'm trying to set up Gradle for the first time, following several tutorials, and I keep getting an exception at line 21. Anyone know how I can solve this, or have any suggestions at least?