# UEFN Validation Error: Disallowed Reference to NavigationSystemV1 After UE5 Migration **URL:** \ **Category:** Issues and Bug Reporting\ **Tags:** unreal-engine, fortnite-creative, unreal-editor-for-fortnite, editor, question, fortnite\ **Created:** [February 20, 2025, 8:21am UTC](https://forums.unrealengine.com/t/uefn-validation-error-disallowed-reference-to-navigationsystemv1-after-ue5-migration/2346276 "2025-02-20T08:21:54Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![Jimbohalo10](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/jimbohalo10/32/961440_2.png) [@Jimbohalo10](https://forums.unrealengine.com/u/Jimbohalo10)\ **Post date:** [February 20, 2025, 7:52pm UTC](https://forums.unrealengine.com/t/uefn-validation-error-disallowed-reference-to-navigationsystemv1-after-ue5-migration/2346276/2 "2025-02-20T19:52:12Z")
hi @Reeyawn , You can only import assets using [Converting Assets into Props in Unreal Editor for Fortnite | Unreal Editor for Fortnite Documentation | Epic Developer Community](https://dev.epicgames.com/documentation/en-us/uefn/converting-assets-into-props-in-unreal-editor-for-fortnite#usingthelegacyprocess) or [Importing Assets in Unreal Editor for Fortnite | Unreal Editor for Fortnite Documentation | Epic Developer Community](https://dev.epicgames.com/documentation/en-us/uefn/importing-assets-in-unreal-editor-for-fortnite) If you try and import from a Migrated Asset in UE5 5.\* engine everything is disallowed in UEFN/Fortnite UE5 PYTHON Is not supported in UEFN as this is a subset of the Enginr Disallowed is for anything not imported in Fortnight see [Asset Validation Issues - Issues and Bug Reporting / UEFN Validation - Epic Developer Community Forums](https://forums.unrealengine.com/t/asset-validation-issues/817504/14) --- _[View the full topic](https://forums.unrealengine.com/t/uefn-validation-error-disallowed-reference-to-navigationsystemv1-after-ue5-migration/2346276)._