My navigation pane disappeared. In trying to fix that, the pane where I edit the code disappeared. I know this is beginner level but there is NOTHING in the documentation to address how to get the navigation pane or code editor panes to open/close properly. Clicking around in trial / error is time consuming and frustrating. Opening and closing does not work. I am afraid to reset. Sigh. Any ideas?
If you can, you can try deleting the ~/workspace/.c9/project.settings and ~/workspace/.c9/metadata/tab* files then reloading the workspace tab.
Append /?debug=1 or /?debug=2 to your url to enter debug mode.
If all else fails, append /?reset=1 to your workspace url to reset the c9 config entirely.