I'm getting this error when I use runData, I can't find anything useful in the stack trace.

Yeah, the stacktrace will not help, scroll up. The program you started exited with code 1. Usually, it also output some error message before that. If not, debug it and find out where it fails.

Yes, as I said, this is not at all a Gradle question. Your code is failing and also printing what the problem is. You see the last lines of the error message at the top of your screenshot

None of my code is in that package though

Maybe it is not your code, but code from a library you use. But either way, the problem has nothing to do with Gradle.

how can I find the problem if it's not telling me where it is

It is telling you where it is, just scroll up more. But yet again, that is not a Gradle question at all, so the question is totally off-topic here. If you need help with that problem, please discuss it in some general Java community.

I was just following what gradle told me to do to get help

Yes, unfortunately it says so for any failed build, no matter what the reason is. I really dislike that. But it does not differentiate what the error is. So the help you get here is, that I tell you that your problem is not a Gradle problem but a problem with your project and if you need more help with that, that you need to seek at a more appropriate place for further help.