In the UI Designer, I've added a form to the Palette and am attempting to insert it into a JTabbedPane in a different form. I click the form in the palette, then click inside the jtabbedpane in the new form, but it doesn't get inserted. Instead, the blue outline that shows where the component is going to be placed just disappears momentarily and that's it.
It worked the first time I tried it (the "nested form" was inserted correctly), however when I ran the application I got a unsupported class version exception (something like that), so I deleted the nested form and tried to re-add it, but now I get this. Restarting IDEA, rebuilding the project, nothing seems to fix it. Any ideas?