# 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:** 4\ **Page:** 1
**Author:** ![Reeyawn](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/reeyawn/32/1125649_2.png) [@Reeyawn](https://forums.unrealengine.com/u/Reeyawn)\ **Post date:** [February 20, 2025, 8:21am UTC](https://forums.unrealengine.com/t/uefn-validation-error-disallowed-reference-to-navigationsystemv1-after-ue5-migration/2346276/1 "2025-02-20T08:21:54Z")
### Summary Getting this error when trying to launch a session: LogValkyrieValidation: Error: Disallowed reference to /Script/NavigationSystem.NavigationSystemV1, Referenced by:Content/Meadow\_Environment\_Set/Maps/MeadowsENV.umap (World), Plugin mount point:/SSMeadows. UEFNValidation: Error: Disallowed reference to /Script/NavigationSystem.NavigationSystemV1, Referenced by:See below for asset list, Plugin mount point:/SSMeadows. UEFNValidation: Error: /SSMeadows/Meadow\_Environment\_Set/Maps/MeadowsENV This level was initially migrated from UE5 and had a few other disallowed object types that I was able to either fix manually or through running a validation fix-up. But, for whatever reason, running a validation fix-up doesn’t affect this error and I have no clue how to fix manually as I can’t seem to find any NavigationSystem info within my level/world or project settings. I have also tried resetting any Navigation Systems settings to default within the World Settings of UE5 project and tried re-migrating but I stil get this error. I’m also not the most experienced with UE5 so I definitely could have missed something. Any ideas what I could be doing wrong? Edit: I was able to copy every actor from one level into a new level created within UEFN BESIDES instanced foliage and then a session will launch and I can play within my level. So, I thought the issue was with instanced foliage and deleted all of them and tried launching session within the imported UE5 levels but still receive the same error. So then I tried going through and individually deleteing meshes, landscape, and foliage until there was nothing except for Island Settings, WorldDataLayers, and WorldPartitionMiniMap and the session stil won’t launch. ### Please select what you are reporting on: Unreal Editor for Fortnite ### What Type of Bug are you experiencing? Other ### Steps to Reproduce 1. Migrate level from UE5 to UEFN 2. Open Level with project in UEFN 3. Attempt to Launch Session 4. Receive error ### Expected Result Session Launches ### Observed Result Project is not valid, see message log for more detail; Run Validation Fix-up; Project validation failed pop-ups and session does not launch as intended. ### Platform(s) windows ---
**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) ---
**Author:** ![Reeyawn](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/reeyawn/32/1125649_2.png) [@Reeyawn](https://forums.unrealengine.com/u/Reeyawn)\ **Post date:** [February 21, 2025, 5:24am UTC](https://forums.unrealengine.com/t/uefn-validation-error-disallowed-reference-to-navigationsystemv1-after-ue5-migration/2346276/3 "2025-02-21T05:24:37Z")
Ahh, I gotcha. Thanks for the info! ---
**Author:** ![system](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/3/713c9d3f58553f0de89543d76a8a3a2779dc9fa4.png) [@system](https://forums.unrealengine.com/u/system)\ **Post date:** [March 23, 2025, 5:25am UTC](https://forums.unrealengine.com/t/uefn-validation-error-disallowed-reference-to-navigationsystemv1-after-ue5-migration/2346276/4 "2025-03-23T05:25:22Z")
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