License servers could not be reached

Some of our team members could not use the Rhino 6 online license today, the prompt pop up when trying to log in to Rhino 6
when I trying to check the license server and is like this :
What can I do under this situation ?

The servers are down? Check Can not retrive Rhino 6 license from License Manager (Hello,

Unfortunately, right now the server is down. We are working to get it up and running as soon as possible.

Sorry for the inconvenience.)

@brian: Another certificate thing? Related to the issue with the validation server I told you about in a recent PM?

Hey All, we’ve been working on this for a couple hours, and are still working to get the Cloud Zoo back up. We’re sorry for the inconvenience.

Thanks for the update, Am replying so I can follow this thread.

We think the Cloud Zoo is back up and running. It’s going to take a few more minutes for all the connections to stabilize, but you should be able to get new leases and see your licenses at now. Again, I’m sorry this happened.

Yes, I’m back up again.
Thank you!

…and now for the debriefing: I’m sure you will want to find out how this happened. Also interesting is why there was no automatic fallback with backup servers at your end or easily discoverable built in Plan B at the user’s end. Could this be another case of software developer’s “oh, that will never happen” design decisions? Maybe you had the same team working on it that did the Boeing 737 Max? At least in your case no-one died as far as we know. Of course with the amount of disgruntlement among the user base this could change. :grin:

Hi Al,

We actually don’t have a firm grasp on what went wrong this time, and are still investigating. But here are the pieces of the puzzle that we do understand:

  1. When Rhino gets a lease from the Cloud Zoo, it remains connected to the Cloud Zoo. This means that if 1000 computers are running Rhino, there are 1000 always-on connections to the Cloud Zoo
  2. When the Cloud Zoo restarts, all those connections are reestablished
  3. If the load is just right, and Cloud Zoo restarts, it can choke on the incoming connections

The solution this time was to increase the server capacity on the back end to handle the incoming connections. Sadly, this took more doing than we expected, which is why we were down for a couple hours instead of a few minutes.

As always, we do what we can to minimize downtime and improve functionality. And, like all the other cloud-based services in the world (even the most highly-redundant, multi-continent, zillion-user ones like GMail), there are issues occasionally.


Hi Brian,

When a computer that has a license in use gets cut off from the Zoo server - not by closing Rhino or shutting down the computer, but because of a network or some other connection problem - isn’t Rhino supposed to continue to work for the ~14 day “grace period” ? (in the same way as shutting down Rhino/the computer normally, then relaunching without an internet connection)

Just trying to understand how the mechanism actually works here.

I guess I don’t understand why this is the best idea. Why not just have the user’s Rhino check back in from time to time, with the interval determined by practical considerations? Why does the user need to be continuously tethered to McNeel?

Just out of curiosity, what’s the order of magnitude of the actual number you are experiencing?

Yep. That’s why only a small fraction of our users experienced any difficulty during the two hour outage.

OK, that’s what I thought. So the main “problem” scenarios that might happen during a cloud zoo server outage would be:

  1. Individual computers who have not used Rhino for 14 days (such as a laptop only used occasionally for travel) and thus need to renew the license in order to run.
  2. Teams of multiple users managed with the cloud zoo - whoever have valid licenses at the time of the outage can continue to work, but no new licenses can be distributed.

Yes. That’s correct.

And we rolled out a new test today (unrelated to the glitch that showed up related to “seat based licensing” error in another thread) of a way for us to very quickly enable a version of the Cloud Zoo that always gives out a license when asked. When we experience another server outage, we’ll be able to turn on this version of it within five minutes, and drastically reduce the impact to our users.

Is it out yet again ?

Maybe… Just opened a new instance of V6 and got this:


But it just wanted me to re-log in which I was able to do…


The cloud zoo servers are up and running.
I’m not aware of any recent outages.

It’s probably somehow my fault then.

Not necessarily.

It sort of looks like when Windows goes “deaf”.
Rhino asks Windows to open the default browser, go to our servers:
And check the status of your license.
Most of the time it works fine.
Occasionally, Windows just ignores the request.

The fastest work-around is restarting Windows.
This seems to free up what ever unknown thing is making Windows ignore the request.

New occurrence of this issue.
I was never barred from opening my Rhino before this silly server based scheme.