Having the same issue... has been happening for at least a few days. Previously never had an issue, not sure what changed. My two iMac desktops cannot connect to each other but my iOS app can connect to both. When I attempt from either iMac I can log into my account, see my other computers and click on one to connect. It opens a new window with the URL https://access.parallels.com/console/?hostid=xxxxxx&agentversion=3.2.0-31423 which ends up staying a blank (gray) screen.
Update... just tried this in Chrome for Mac and it is working. It appears the issue is with Safari.. but I quite literally hate chrome and prefer to use Safari so a resolution would be nice. I'm currently running Safari 11.1 (13605.1.33.1.2) on macOS High Sierra 10.13.4.
Last edited: Apr 12, 2018