Am not sure how to troubleshoot? I check the application logs and DBs logs to compare the time but I could not notice any abnormalities. MessageSecurityException: Paired key does not exist” Problem You’ve noticed that some desktops are in Agent Unreachable state in the VMware Horizon 7 Administrator console and clicking on the elipsis displays the following detail: They allow us to know which pages are the most and least popular, see how visitors move around the site, optimize our website and make it easier to navigate. Session has Expired, Please Restart Horizon Client to Connect.