With the recent release of Firefox Version 43 (December 15th, 2015), Mozilla has removed support for NPAPI plug-ins which impacts the F5 plug-in used for Secure Connect access to GTS Online.
Details on this Firefox update can be found here: Firefox Version 43 Release Notes
This poses a challenge for GTS customers who need an alternate browser to Internet Explorer for GTS Online access.
Fortunately, there is a solution with Firefox ESR, which is designed for users who need a more stable, less-frequently updated version of the browser. Additional technical details on this Firefox variant can be found here: Firefox ESR Overview
GTS customers are advised to use this browser for GTS Online access if Microsoft Internet Explorer 11 is not a practical option.
Firefox ESR can be downloaded from here: Download Firefox ESR (US-English)
Please contact GTS Customer Support (email firstname.lastname@example.org or http://support.gtsservices.com) if you require further assistance.