I use IntellijIdea Community 2020.1 with Gradle. I had to set "Settings > Build, Excecution, Deployment > Gradle > Build and run using = IntelliJ Idea". Because only in this case IDE initializes forms properly. But IDE does not include folder Resources in archive when I create Jar-file . I think, its because this folder places out of src directory. Now I solved this problem by adding Resources manualy in "Output layout" according the answer Intellij resources not in built artifact.
So the question is "Is there a way to include Resources in Jar by another normal easy way?"