Just wanted to make a note - I figured out why “Add transpose track” would instantly crash my Cubase session. There was a particular audio event in one of my tracks that caused the error. It was set as the “Standard - Solo” warping algorithm, and once I changed this setting to “elastique”, I was able to add the Transpose track normally.
Other tracks in the same session were set as “Standard - Solo” also, but these did not trigger the issue. This one particular chunk of audio was misbehaving and caused the entire app to crash.
Some more context - I ported a project using AAF from Digital Performer, and have been continuing working on it in Cubase.
So - to recap - the issue is solved, but I wanted to make note of it here, in case it helps anyone else. Cheers!