Empty folder pane on Mozilla Thunderbird 9.0.1

After working with some update, there is something wrong with my Mozilla Thunderbird 9.0.1. I see an empty/nothing in the left folder panel. And to make it worse, the title tab at the top of the pane is also blank...

I've tried to reinstall the TB, but it seems like the problems still occur. After searching and looking for the solutions, I think this URL solve the problem:

http://getsatisfaction.com/mozilla_messaging/topics/no_side_panel_and_folders

How to fix it:

1. Close the TB
2. Open the Windows Start menu
3. In the "Search programs and files" box, type in %APPDATA%
4. Click the "Roaming" item that appears on the menu
5. In the Windows Explorer windows, choose Thunderbird > Profiles
6. Find and remove "folderTree.json",
7. Restart TB... That fixes it...