The certificate used by Globus Connect Personal endpoints to securely connect to Globus expires on August 9, 2016. We released updated packages with new certificates a few weeks ago. If you have not yet updated your Globus Connect Personal installation, you must do so before August 9th so that your endpoint continues to work.
Instructions for updating to the latest version of Globus Connect Personal are provided here. Please contact firstname.lastname@example.org if you have any questions.