Issue
I have created some custom UI components in JavaFx, but when I imported the jar to the Scene Builder it says there are no UI components
Solution
I figured out the problem after searching all over the net.
It was a problem of compatibility between the compiler and SceneBuilder.
I was using JDK 14 and JavaFX 14 to compile the components and importing the jar to SceneBuilder 11.
So I installed SceneBuilder 16 and problem solved.
And of course the UI components must meet the standards, extending a Node and all that.
I hope this is useful to you.
Answered By - Hamlet