1. open inkscape(.com so you get a console window)
2. click text tool (F8)
3. click-drag to create text rectangle
4. type some text
5. move mouse (still text tool mode) outside text rectangle
6. click-drag to create 2nd text rectangle
7. see assertion error

Windows 7 pro, SP1

1.0beta1 (fe3e306, 2019-09-17)

Confirmed on Windows 10, Inkscape 1.0beta1 (3c9e8b0c0e, 2019-09-26).

Could you please file a bug at https://inkscape.org/report?

Done. https://gitlab.com/inkscape/inbox/issues/935

Thanks!