Crash when trying to change Overlay Subscreen Editor settings

[Asuna Yuuki Nagato]

ZQuest Classic Editor
Version: 2.55 Nightly (Alpha 118/119)
Tag: 2.55.0 Nightly (Alpha 118/119)
Build Date: 22nd January, 2024 at @ 21:17:49 EST
Dev Signoff: Unsigned
QR:##B343AFAF01C281A00DA58A4211A608DFDF080001362A0410FC5306FE2A274100381B02044031300000065824C00000000000D0032321000000000000000000000000000000000200000000000000000034866C3140320200000000000000000000000000##

Steps to recreate:

1. Open "Edit Subscreens" window (Quest->Misc Data->Subscreens)
2. Select "Overlay" tab
3. Click "Edit" and observe "Overlay Subscreen Editor" opens
4. Select Options->Subscreen Settings

The switch statement in TextField::setSwapType(int32_t) then does this:

Exception thrown: read access violation.
**this** was nullptr.

[Asuna Yuuki Nagato]

I can't recreate this anymore. Instead I get a msgbox titled "Subscreen Settings" which says:

No settings for overlay subscreens yet!

With 'OK' and 'Cancel' buttons - we probably only need 'OK' though.