Undo/redo not working

hello my name is darren and I have a problem with the undo and redo they are greyed out and not working im using a mac can any one help please

sorry i should have also said in using Rhino version 5.5.4

Hi Darren -

I just installed Rhino for Mac 5.5.5 and see the same thing on my machine.
I went and searched for previous occurrences of this behavior and only came up with this one:

At that time, no one was able to reproduce that issue and so it must somehow be related to a specific hardware - macOS combination and configuration.

I’m afraid I don’t have anything useful to suggest. The current version is 7.1 and undo is working as it should with that version on that same machine here.

thank you very much for your time you say you are using 7.1 is that on a mac and if so where did you buy it

Hi Darren -

Yes, that is also on the Mac.

You can find a local reseller from the “Buy” page:

Or, to start with perhaps, download an evaluation version from this page: