Unable to use DDD...

Hi,

I am new to DDD. I have been using DDD since couple of days. Since
yesterday I am not able to use DDD because after I launch it, DDD goes
into "busy mode" with the status line at the bottom showing the
message "Opening session "104aec...."". There is a green indicator at
the right corner that keeps blinking. The problem started yesterday
after I forcibly closed DDD, by clicking on the "Exit" menuitem, when
my program that I was debugging hanged. And now I am not able to use
DDD. How do I make DDD work again? I am using Ubuntu 12.04 LTS 64 bit
and DDD version is 3.3.12.

Thanks and regards,

~Plug