Rhino 5 on Big sur - Unhandled exception validating license?

Does anyone know how to proceed?
I just bought a new MacBook pro 16" and the Big Sur OS might be the problem here. It does not like photoshop so I’m suspecting that is where the problem lies. I’m running Rhino 5.5.5.

Thank you!

Yes, Rhino 5 for Mac is not supported on Big Sur. You’ll need to upgrade to Rhino 7 or use an older macOS that is supported for that older Rhino version. See Rhino - System Requirements for Rhino 5

Try the 90 day evaluation of Rhino 7 for Mac on the Download page.

Thank u! I was afraid of that.

Just ran into this myself, now! Rhino 5 was working okay for awhile in Big Sur for me albeit some bugs, now I the license I paid for won’t validate, because Im on Big Sur? What a mess. Makes me think twice about investing further with Rhino.

Hi Brian, my license for Rhino 5 now won’t validate on with Big Sur. It’s also giving me an error saying that “Your License Validation Grace Period has Expired” What does that mean? and how can I fix this? I already own this “license” It’s not a trial version.

V5 is not supported on any macOS newer than Mojave.
You’ll need to upgrade to V7 is you want to run Rhino under Big Sur.

As John mentioned, v5 for Mac won’t run well on Big Sur and isn’t supported but your license issue sounds separate. Email Sales@McNeel.com from the email address you registered your license to and include the license key to ask about the error message.