Any idea why the Process Bar in the Tempo Editor is greyed out? In a new session it works - could I have switched something off by accident?
I think you can only use Tempo Track’s processing when you’ve switched on the tempo track. If you don’t switch on the tempo track you’ll be working in the projects’/fixed tempo which won’t allow you to do any tempo-related editing.
Please refer to Nuendo’s manual: https://steinberg.help/nuendo/v10/en/cubase_nuendo/topics/editing_tempo_and_signature/editing_tempo_tempo_modes_c.html
Hope this works?