When trying to import the example fabric project via the build.gradle file in IDEA, I get the following error as gradle tries to to build.

Caused by: java.lang.ClassNotFoundException: org.gradle.api.internal.plugins.DefaultConvention

I don't think that gradle is outdated, as it is shipped with IDEA which is up to date.

The full stack trace is here

Idea should be using the gradle as defined in project's gradle wrapper. Check if idea is importing the gradle project using the local gradle wrapper from the project.

The gradle plugin is also up to date

I set it to the local gradle wrapper

Mind close the project in idea, remove it from recent projects, and then open the build.gradle file fresh and see the results?

I had this issue with two seperate projects I wanted to create now, I think its a problem with the Jetbrains Gradle Plugin

Hmm, what idea version are you using? Mind update to 2020.1

Seems like I was still on 2018.3 without getting an update notification, my bad.
Works now on 2020