'gradlew runClient' fails everytime in ExampleMod

[TrustyTrojan]

I am trying to run the client from the Example Mod that forge provides and no matter what I do, the exceptions in the log file I attached always lead to a NullPointerException error. The log hinted at some LWGJL jar files being the issue, but when I deleted them and ran the command, it automatically re-downloaded itself (now I know it's a dependency). I have reinstalled the JDK on my Ubuntu system several times (openjdk-8-jdk) and no change. Help please?

latest.log

[Ugdhar]

1.12 is no longer supported on this forum due to age.

Please update to a modern version to receive support here.

 

More information on supported versions can be found in the LTS link at the top of every page.