IntelliJ IDEA - GUI Designer - Cannot load Preview form

Question

I have a real trubble for a beginner)

When I try to see Preview while working in GUIform (even when class is empty), I see an error:

Cannot preview form '.../SimpleG.form'
Reason: cannot load /com/intellij/uiDesigner/FormPreviewFrame.class

// I have installed plugin JFormDesigner and didn't find how/where to install UIDesigner plugin.

Project SDK 1.8;

Project language level SDK default (8)

Answer 1

Looks like IDEA-237293. Will be fixed in the next release (around May 26th).