Intellij (Swing) GUI not compiling because of Gradle

Question

I have a Gradle project and I am trying to create a GUI (Swing, using Intellij); however, I keep receiving an error on compile. The exact same GUI code can be run on a stand

Answer 1

This seems to be an issue between Gradle and Intellij. A solution is to migrate to Maven. The .form file (generated by Intellij) for the GUI should be initialised at the line frame.setContentPane(new ApplicationGUI().rootPanel); but this does not happen. There are no issues when using Maven.