Empty folder pane in Thunderbird email client

[Teo En Ming]

Hi,

Although I have upgraded Ubuntu 13.10 to Ubuntu 14.04 LTS, I still get 
an empty folder pane in Thunderbird email client, from time to time. I 
have tried the solution in the following link but it doesn't help.

http://kb.mozillazine.org/Empty_folder_pane

Does anybody know how to solve the problem?

Thank you.

-- 
Yours sincerely,

Teo En Ming
Singapore