Currently ConnectionOpen sessions are failing due to a server issue.
In order to resolve this matter as swiftly as possible, we have set up a new server, and have released an update for ConnectionOpen, v3.4.2, which you can download now to fix this problem.
After updating to v3.4.2 you will be able to create and connect to sessions again.
Download ConnectionOpen v3.4.2 for Windows and MacOS here.
We apologize for any inconvenience caused, if you need our help, support or have any questions, please get in touch and we will be happy to assist you.