Take me back to the start
If I have made en error when adding values to the plugin job parameters I get a page telling me that I've tried to add invalid data. The page gives me the options Back and Close. The Back button takes me to the Finish page where I can start my plugin. But since I haven't changed the values of the parameters I get to the invalid data page.
The back button should let me re enter the parameter values. The best solution (from the users perspective) would be if the values from the previous configuration are left and the user is notified which value he should change.