Theme editor - Clicking add or remove button under a Type's style causes theme editor window to close

[nickjfrench]

Godot version

4.0 beta 17

System information

Windows 10, GTX 1080ti (Driver #527.56), GL_Compatibility renderer

Issue description

Within Theme Editor, if I add a new Type (e.g. RichTextLabel) then I click the plus (add) next to default_color it closes the theme editor window. This happens with trash can (removing) icon too.

I've tried this with multiple Types and styles, all do the same. See video below.

ThemeEditor-ItemStyleBug.mp4

EDIT: Happens on adding Fonts too, both on the pencil icon then on the New FontFile options.

Steps to reproduce

1. Create new theme
2. Save into file
3. Add new Type (e.g. RichTextLabel)
4. Add new style or remove existing style (e.g. default_color)

Minimal reproduction project

N/A

[EntityinArray]

Happens to me on Godot_v4.0-rc1_win64 as well.
It also throws this error as theme editor closes:

  editor/plugins/theme_editor_plugin.cpp:2289 - Condition "edited_theme.is_null()" is true.

[akien-mga]

Duplicate of #72271