Losing license until next restart problem

It’s been happening more often recently to the point that it seriously gets in the way of working.
After a few hours of working in Rhino, and several instances open, at some point when trying to open a new instance, I get this:
(looking for license dialog)
It never ends, and when canceling and trying to log into my Rhino account it gets back to the same endless loop.
After 3 attempts, I end up with this:

So not possible to open any Rhino anymore, until I restart the computer.
This is very annoying. Is there any way to fix this behavior?

(Rhino 6 SR 30).



Try a repair on your install,
go to add or remove programs, single left click on rhino v6, and then click modify, then repair.

restart your machine and then try rhino again.

If that works, you are done, if not then uninstall, and reinstall-

if that works, you are done,
if not, call us at Technical support (206) 545-6877 or e-mail us at tech@McNeel.com

Hello @jarek,

This is usually due to a hidden Rhino. In Task Manager, make sure to find any hidden Rhinos and close them when this happens.

Thank you both. I will try these methods (since I can’t easily reproduce the problem it may take a while to know if it worked)



Hi Andres,

I just experience this again, looked for “hidden” Rhinos in Task Manager but nothing out of ordinary is there. So again can’t start a new Rhino until restart.
One thing that may be a culprit is I was opening 3rd instance of Rhino while the 2nd instance was still starting up. Could that possibly mess up the communication with the license system?

I am looking for a way of not having to restart every time it happens - it’s a big productivity loss.
(and yes, I tried repairing and reinstalling, that did not solve it).



Hi Jarek,

What you describe is indeed possible in Rhino 6 (We’ve made some major changes in 7 so that this occurs less frequently). In Windows, all Rhinos are connected for licensing questions. If there is a Rhino in the background (which would happen if you open multiple documents at the same time), then the first document to launch in Rhino 6 needs to finish its licensing process before the second process can start. If the first Rhino is requesting input, the second Rhino won’t start until the input is taken care of.

In essence, for absolute reliability, make sure that only one Rhino is open when you see the Please Wait dialog (hence my suggestion about hidden Rhinos).

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