AddVerseField reports success but the field never reaches the widget's generated Verse class

Summary

VerseFieldsToolset.AddVerseField returns true and ListVerseFields shows the new field, but the field is never a member of the widget’s generated Verse class, so any Verse code referencing it fails to compile. The failure is silent, nothing reports an error until an unrelated-looking Verse build error appears later.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Verse

Steps to Reproduce

  1. Create a Widget Blueprint with parent class UserWidget, e.g. /myproject/Probe/zz_WBP_Probe
  2. Call VerseFieldsToolset.AddVerseField(WidgetBlueprint, “ProbeOpacity”, “float”, “0.75”, Public). It returns true.
  3. Call ListVerseFields on the same asset. It returns: ProbeOpacity, type float, visibility Public, is_var true.
  4. Compile and save the Widget Blueprint.
  5. In a .verse file, write: W := Probe.zz_WBP_Probe{} and then reference W.ProbeOpacity
  6. Build Verse.

Expected Result

The field is a member of the generated Verse class and the code compiles. AddVerseField’s own schema description states the field “is reflected into the widget’s generated Verse class”.

Observed Result

Error 3506: Unknown member ProbeOpacity in zz_WBP_Probe.

The widget class itself resolves correctly. only the field is missing. Recompiling the widget, saving, and rebuilding Verse do not change the result.

Reproduced through two independent call paths: Epic’s UEFN MCP VerseFieldsToolset, and Python calling the same AddVerseField UFUNCTION directly inside the editor. Both produce the identical error, so this is not a defect in a wrapper layer. Adding a field by hand in the widget editor’s Verse Fields panel has not been tested.

Impact: a Widget Blueprint can be displayed from Verse but cannot be driven by it, so programmatically authored UMG is display-only.

Platform(s)

Windows