This error can occur when opening or closing any version of Rhino for Windows.

It is very difficult to tell what is going wrong from these very unhelpful & painful Windows dialog boxes. The server in the Server Busy dialog is not referring to our license server.

It is a somewhat generic Windows error dialog This is related to a COM server running on your computer itself.

Learn about Microsoft COM Clients and Servers here.

1. Apply all Microsoft updates.
2. Download and install the latest Rhino here.
3. Reboot the computer.
4. Open Windows TaskManager and end the task for any Rhino processes that are still open.
5. Reboot at least every week as part of your computer maintenance.

You can discover when others are reporting about this message on our Support Forum. Here is one report here and this one relates to a plugin Enscape here too.

Mary Fugier tech@mcneel.com 9-24-2023