The category is set to Workspace, please confirm that you have installed Workspace on your dedicated server and version of all components (can be found in Control Panel > Update section).
By the way, have followed the guide? Here is the link to it:
Thank you for the info. Unfortunately, we do not have any guides on how to run Workspace with a proxy service in front of it, as it already uses quite complex proxy structure for communication of all services. I believe additional proxy causes such issues.