Still losing custom UI with every update

It’s possible. Is your custom toolbar still in default or did you actually create a separate .rui for it?

So, here is the general procedure -

Make sure Rhino is closed.
In your backups, find a date before the settings got nuked.

  • In the backup, navigate to
    C:\Users\<your username>\AppData\Roaming\McNeel\Rhinoceros\8.0

  • Inside that folder, copy the entire settings folder somewhere.

  • If you have made a custom .rui, in your backup it will be in
    C:\Users\<your username>\AppData\Roaming\McNeel\Rhinoceros\8.0\UI

  • Make a copy of that file too.

  • Now, back in your computer (not the backup) navigate to the same folder -
    C:\Users\<your username>\AppData\Roaming\McNeel\Rhinoceros\8.0

  • Rename the settings folder there to something like settings-old

  • Put the copy of the settings folder you made from your backup in the same directory
    (make sure it’s still named settings)

  • If you had a custom .rui, go to
    C:\Users\<your username>\AppData\Roaming\McNeel\Rhinoceros\8.0\UI

  • Rename the original custom .rui to something like xxx.rui.old

  • Put the copy of the .rui from your backup in that folder.

Now, start Rhino. If all has gone well, it should look like it did before the settings were nuked.