Unable to add basic cards to my deck

When I try and add cards to a new deck I’ve made, I have to switch from image occlusion to the basic card format and the app doesn’t let me, giving me this debug info;
Anki 24.06.3 (d678e393)
Python 3.9.18 Qt 6.6.2 PyQt 6.6.1
Platform: Windows-10-10.0.22621

Traceback (most recent call last):
File “aqt.studydeck”, line 165, in accept
File “aqt.studydeck”, line 169, in accept_with_callback
File “aqt.deckchooser”, line 99, in callback
TypeError: ‘NoneType’ object is not subscriptable

I’ve tried uninstalling and reinstalling it, closing the programme down, disabling image occlusion enhanced and opening the programme with shift pressed down.

Please see Troubleshooting - Anki Manual