# UEFN not launching **URL:** \ **Category:** Issues and Bug Reporting\ **Tags:** fortnite-creative, unreal-editor-for-fortnite, question, fortnite\ **Created:** [October 15, 2024, 4:10pm UTC](https://forums.unrealengine.com/t/uefn-not-launching/2069792 "2024-10-15T16:10:03Z")\ **Posts on this page:** 1\ **Showing post:** 14
**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:** [November 3, 2024, 8:48pm UTC](https://forums.unrealengine.com/t/uefn-not-launching/2069792/14 "2024-11-03T20:48:18Z")
hi @FreshBeezy looking in the past [UEFN crash on startup assertion failed. - General / Issues and Bug Reporting - Epic Developer Community Forums](https://forums.unrealengine.com/t/uefn-crash-on-startup-assertion-failed/805583/5) The Dx12 have GPU errors, the main errors are in SM6 hence use SM5 which my pc uses [[Solved] How to fix Fatal Errors in UEFN related to Graphic Cards and Shaders and Derived Data problems](https://forums.unrealengine.com/t/solved-how-to-fix-fatal-errors-in-uefn-related-to-graphic-cards-and-shaders-and-derived-data-problems/2080832/2) Windows 11 usually has these errors and Windows 10 works fine. Some software based on UE5 works well since 2018, The Official equivalent needs Windows 11 and Directx12 because the shaders are model 6.5+ My development is done on Windows 10 latest and UEFN fault finding on Windows 11. There was once an idea that this was because Texture - Static mesh show be Power 2 of 2 2023 projects crash more often but nobody really knows why --- _[View the full topic](https://forums.unrealengine.com/t/uefn-not-launching/2069792)._