4.2B3: Crash on clicking inside Text Comparison popup

Just discovered a 100% reproducible crash as follows:

1. Make Phil 3:12 the active reference
2. Hit F7 to bring up the text comparison popup
3. Click inside the popup to launch the full Text Comparison window.
4. Kaboom.

I don't experience the crash if I go to the main TC window directly, and enter the same reference. It's only when clicking inside the TC popup that it occurs.

Thanks
Richard