Open a jEdit view, get your dockables, split panes, etc just the way you like. Open a project and get the files open in the splits, just where you want them. Name the view so it is easy to find. Now save the session. Now open a second view, open a different project in that view, get dockables, splits, files, etc just right. Name the second view. Save this "session" with a different name.
Now close and reopen jEdit. The view you last closed will be restored quite nicely. The other will not. That's OK, that's why you installed Sessions plugin, right? So use Sessions to Manage Sessions and Change To the session you want. Oops! Both views just go nuts. The wrong files are open in one, no files are open in the other, dockables are wrong, everything just looks like crap. Hmm, that was odd. Oh well, switch back to the other one. Well Joy!! No difference. Still usesless.