# Un5 is crashing on start a project.

**URL:** <https://forums.unrealengine.com/t/un5-is-crashing-on-start-a-project/1696860>\
**Category:** Getting Started & Setup\
**Tags:** package, assertion-failed, unreal-engine, crash, question\
**Created:** [February 18, 2024, 8:24am UTC](https://forums.unrealengine.com/t/un5-is-crashing-on-start-a-project/1696860 "2024-02-18T08:24:25Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![DeanFromTokyo](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@DeanFromTokyo](https://forums.unrealengine.com/u/DeanFromTokyo)\
**Post date:** [February 18, 2024, 8:24am UTC](https://forums.unrealengine.com/t/un5-is-crashing-on-start-a-project/1696860/1 "2024-02-18T08:24:25Z")

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Hey y’all,

My project keep crashing on start. What I did was I clicked to package the project. Then, I tried to open the console log. UN crashed that time. Since then I cant open the project.

Error log shows this:

Script Stack (0 frames) :

[2024.02.18-08.08.37:872][0]LogWindows: Error: appError called: Assertion failed: !HasAnyFlags(RF\_NeedPostLoad) [File:D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\Materials\MaterialInstance.cpp] [Line: 2444]

[2024.02.18-08.08.37:872][0]LogWindows: Windows GetLastError: The operation completed successfully. (0)

 ![Error_01](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/d/d/8ddef7db5a470c9e2ce91eae3c1965f504399357.png)

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**Author:** ![FrostyJas](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/frostyjas/32/1194640_2.png) [@FrostyJas](https://forums.unrealengine.com/u/FrostyJas)\
**Post date:** [February 18, 2024, 10:59am UTC](https://forums.unrealengine.com/t/un5-is-crashing-on-start-a-project/1696860/2 "2024-02-18T10:59:09Z")

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Greetings @DeanFromTokyo

Are you using Nanite with this? Also, the first thing I’d try is enabling SM5 and changing to DirectX 11 and then try to reopen the map/project. Let me know if it allows it to open. If it does and you are using Nanite, try turning off Nanite after you get it launched and then change back to CM6 and Dx12.

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**Author:** ![system](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/3/713c9d3f58553f0de89543d76a8a3a2779dc9fa4.png) [@system](https://forums.unrealengine.com/u/system)\
**Post date:** [July 24, 2024, 11:03am UTC](https://forums.unrealengine.com/t/un5-is-crashing-on-start-a-project/1696860/3 "2024-07-24T11:03:36Z")

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