How to Fix Verse Constructor Errors After the Latest UEFN Update

UEFN just launched a new update with Verse updates and fixes. One of them included:

"The Verse compiler now errors when initializing a field after calling a delegating constructor in an archetype expression. This fixes missing validation, and now correctly enforces Verse’s object construction semantics."

You can read more directly on the documentation:
37.50 Fortnite Ecosystem Updates and Release Notes

The Fix

Move the delegating constructor call below all field initializers. In the case of this example from our Mystery System we must move the MakePlayerProfileData below where we are setting the new value for the GamesPlayedAsImpostor stat.

What's new?

The Verse compiler now enforces a stricter rule for how objects are initialized. In previous versions, you could initialize fields after calling a delegating constructor inside an archetype expression. That behavior is no longer allowed.

This update ensures that all field initializations happen before any constructor calls, bringing Verse in line with consistent object construction semantics. It prevents potential runtime issues caused by partially initialized objects and makes the construction order clearer and safer.

If your code initializes fields after a delegating constructor, the compiler will now display an error. To fix it, move all field assignments above the constructor call. Live islands will continue to function, but you’ll need to follow this rule to republish your projects.