Kiran, did it happen after some upgrade or simply over night? I'm unaware of any problems like that. If there isn't anything obvious in the logs, as Harshal suggested, please contact our support team to sort this out.
We made a change to the rtm.config file to increase the timeout value to 2000ms. Other than that there were no other changes. Not very sure if this is the reason. I would have 100+ users for DC-RUM . How can I restore the favorites for them? going forward how would I do a backup of this setting at user level?