Possible bug SynchronizeCPlanes

I think there is a bug in SynchronizeCPlanes at least when using a legacy Rhino 5 32 bit file (from a Windows 7 box). It may be a 64 to 32 bit problem so I’ve been reluctant to call it. Currently running Windows 11 (AM5 high end box with RTX card) all drivers BIOS etc uptodate.

Anyway here goes, I have a model with two Constuction Planes the WCS (default) and another created one. Generally I have been working on the created one call it Square1. If i change the view from back to front the Plane used by Rhino defaults to the WCS. If I change the Option under Tools, Ooptions, Modelling Aids to Universal Construction Planes I can then define the Named Plane to use in the Viewport and it will correct the view.

If you run the SynchronizeCPlanes command from the command line when you have two or more viewports with the WCS showing and you pick a viewport with the custom Square1 as the base option the other viewports do not update and have to be individually changed. The help file simply says click in source viewport and all will update. This is not happening.
It does allow you to get the view correct just not as outlined in the help files. Note it worked perfectly in Rhino 5 (32 bit). I have installed Rhino 5 on Win 7 64 bit but have not tested the file on that. The potential bug is there on Rhino 7 (last SP) and 8 WIP (current).

I’m used to hunting through Rhino help files to find useful odd commands that are in there but only at the command line. I was using Clipping Planes way back from the command line in version 3 or earlier. Most times Rhino has what high end systems in there even if slightly discreet - good on McNeel for their documentation some of the best out there ever.

I’m quite happy to run with it as I found the work around, but it might be useful for the Dev team to be aware of this behaviour.

Reflecting on the above behaviour the one thing that is different in the files is the creation of a Block (3D geometry). This was created on the fly whilst using a Custom Constuction Plane. The Block of course uses the WCS as it’s base point. The block was then manipulated to where I wanted it and orientated to the current custom plane.

There is a good thread about Block and Plane orientation here

I suspect this SynchronizeCPlane problem is linked to this Block use. Could be wrong.
I’ve used 2D Blocks plenty before so am pretty familiar with them and how useful they are especially at keeping file size down and editing multiple items. Mainly in transport design such as rail carriages.