Server busy error when starting Rhino 8

Hi there, when we’re starting Rhino 8 we get a server busy error. When clicking the switch to button it opens the Windows Start menu repeatedly and finally it reports that it cannot communicate with the Zoo License server. When we run the ZooDiagnostics tool all 5 tests pass without failures so the feedback from Rhino 8 is very strange. Any clues what could be causing this behaviour? We need to have this fixed before we can deploy the new version to all users in our company. We’re currently on Rhino 7 where we do not see these issues.

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A similar report here last week with some additional troubleshooting methods.

There was no resolution, but until your post seemed isolated. @dale

Hi Japhy, thanks for your response. I have added the inbound and outbound rules as described but unfortunately it did not help. We’re currently running Rhino 7 with the Zoo license manager without any issues and also the ZooDiagnostics tool passes all 5 checks without any issues, if the Firewall wasn’t working well I guess it would fail too, right? In the meanwhile I found that when I launch Rhino 7 and immediately after that my Rhino 8, it seems to work too??

Rhino uses a Windows service to check for updates and download them in the background. This is the same service Windows and other applications share. What’s happening is Windows is getting a “log jamb” of requests for the service and it is reporting back to Rhino that is is too busy.

You have a couple of options.
If you start Windows and leave it alone for a while, the update requests will eventually finish so Rhino will start without a gripe.

The other option is to turn off checking for updates in Rhino.
If this is V5 of V6, you can turn off checking for updates in Rhino Options, as there will be no more Service Release updates for them.

If this is V7 or V8, that’s not a good idea.
Service Release updates come out every month fixing bugs.

Hi John, thanks for your reply. Unfortunately the issue is still happening when I am logged on for a long time on my laptop, not only when starting Rhino 8 too early after login. Even when I have disabled the update feature in my preferences the issue persists.

Maybe temporarily disable Windows updates, and restart the computer.
If you Google the problem, you’ll see this can be a stalled Windows update.

My Windows update settings are centrally managed by my organization, no option to turn off my settings. Nevertheless the status shows that I am up to date and my update history doesn’t show any missing or stalled updates, all have been installed successful.

The one thing that I do not get is that my Rhino 7 is working flawless with the Zoo license server, it’s just the newly installed Rhino 8 that’s throwing up this error. I have also figured out that when I start my Rhino 7 first and shortly after I start my Rhino 8 it works too. But I do not want to introduce this workaround to our community, as a matter of fact we’re planning to uninstall Rhino 7 upon installation of version 8 so it should without this dependency…

Hi @ronald_van_den_boome - it sounds like you’re using a LAN Zoo license for Rhino 8. Do you get the same “server busy” error when you start Rhino 8 in Safe Mode?

Hi @brian , unfortunately yes. Both do not start and throw up the Server Busy error.

Yes, same here.

Having the same issue, have to crash the program to reopen it

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Small update, we’ve installed Rhino 8 on 4 systems and they all have issues communicating with the LAN Zoo so it becoming a showstopper for deployment. Any updates, tips are highly appreciated.

i have a similar problem:


Unfortunately, we have the same problem within our organization.

We also use Rhino 8 with the latest version for the Zoo Server.
Licenses for Rhino 7 and Rhino 8 are stored on the Zoo Server.
The licenses for Rhino 7 can be retrieved normally, but when trying to obtain a Rhino 8 license from the client, no connection to the Zoo Server can be established.

What has been noticed, however.
If we want to retrieve the 8 license via a virtual machine, the communication with the Zoo Server works.
Only with physical hardware/laptops/workstations can no connection to the Zoo Server be established.