The certificates used to sign Desktop Central binaries has expired on 28-12-2014, you might face problem in establishing remote connection. 

This issue has been fixed in 90108 build. Please migrate to the latest build for the remote control to work properly. Please find the build url here for Enterprise Edition and MSP Edition

Incase, if you are unable to migrate to the latest build immediately, follow the below steps to resolve the Issue :

1. Open Control Panel in viewer computer.
2. Right click Java icon and click open.
3. Click on "Security" tab.
4. Set the "Security Level" to Medium. ( If level is set to medium, just a warning message appears and the customer can proceed by accepting     the prompted warning. )
5. Try remote control after restarting the browser.

Please note this is workaround steps. The ideal method is to upgrade to the latest build 90108  

Regards,

Vijay.