# UEFN cook\_failure since latest update – Array index out of bounds during cook 

**URL:** <https://forums.unrealengine.com/t/uefn-cook-failure-since-latest-update-array-index-out-of-bounds-during-cook/2728812>\
**Category:** Issues and Bug Reporting\
**Tags:** unreal-engine, unreal-editor-for-fortnite, question, fortnite\
**Created:** [June 15, 2026, 2:56pm UTC](https://forums.unrealengine.com/t/uefn-cook-failure-since-latest-update-array-index-out-of-bounds-during-cook/2728812 "2026-06-15T14:56:37Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**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:** [June 15, 2026, 6:36pm UTC](https://forums.unrealengine.com/t/uefn-cook-failure-since-latest-update-array-index-out-of-bounds-during-cook/2728812/2 "2026-06-15T18:36:04Z")

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hi @CODEHOANI

From the log looks like your installation try to

[Verify UEFN](https://forums.unrealengine.com/t/urc-exe-and-urc-dll-get-flagged-as-malware-from-microsoft-defender/1802519/5)

If this does not work you need to uninstall UEFN and re-install because you are missing major parts of UEFN

![BUG2NeedVerify](https://d3kjluh73b9h9o.cloudfront.net/original/4X/0/4/0/040cf426dd37e1741b5da0febbcfb7c208843dd7.png)

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