What to do when the editor won't start

First of all, read this webpage: http://www.eclipsezone.com/eclipse/forums/t99010.html. A lot is explained there about how to start the osgi console, add extra options to an eclipse application that will provide more feedback.

The bundle could not be resolved. Reason: Missing Constraint …

In the Launch Configuration for your editor, choose the Plug-Ins tab and do the "Deselect All" -> "Add Required Plug-Ins" magic. Or proceed as in the srticle mentioned above.

The bundle fails to load its classes

Try adding a BundleActivator to the respective bundle.