# Assertion Failed Crash: SerializeNum

**URL:** <https://forums.unrealengine.com/t/assertion-failed-crash-serializenum/491332>\
**Category:** Platform & Builds\
**Tags:** assertion-failed, serialization, unreal-engine, question\
**Created:** [November 26, 2021, 10:40am UTC](https://forums.unrealengine.com/t/assertion-failed-crash-serializenum/491332 "2021-11-26T10:40:11Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![AdamBaker2](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@AdamBaker2](https://forums.unrealengine.com/u/AdamBaker2)\
**Post date:** [November 26, 2021, 10:40am UTC](https://forums.unrealengine.com/t/assertion-failed-crash-serializenum/491332/1 "2021-11-26T10:40:11Z")

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LoginId:a1a5dc4a4132c9d353db9293971927e1  
EpicAccountId:44a4344e3fca4f9b9eb555014970156b

Assertion failed: SerializeNum \>= 0 [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 1152]

UE4Editor\_Core  
UE4Editor\_Core  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_DerivedDataCache  
UE4Editor\_Core  
UE4Editor\_Core  
UE4Editor\_Core  
UE4Editor\_Core  
UE4Editor\_Engine  
UE4Editor  
UE4Editor  
UE4Editor  
UE4Editor  
UE4Editor  
kernel32  
ntdll

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<div class="post-metadata">

**Author:** ![Javi\_Garcia](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/javi_garcia/32/1046384_2.png) [@Javi\_Garcia](https://forums.unrealengine.com/u/Javi_Garcia)\
**Post date:** [October 14, 2022, 3:24pm UTC](https://forums.unrealengine.com/t/assertion-failed-crash-serializenum/491332/2 "2022-10-14T15:24:09Z")

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Same fail.  
somebodie knows how to fix it?

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<div class="post-metadata">

**Author:** ![Ranettebr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Ranettebr](https://forums.unrealengine.com/u/Ranettebr)\
**Post date:** [July 27, 2023, 2:01pm UTC](https://forums.unrealengine.com/t/assertion-failed-crash-serializenum/491332/3 "2023-07-27T14:01:09Z")

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Hello everyone! Faced with the same problem.  
Assertion failed: SerializeNum \>= 0 [File:Runtime/Core/Public/Containers/Array.h] [Line: 1253]

If it appears on iOS, it means that in your scene there is an object which has a property FVector. On other platforms FVector is typedefed to UE::Math::TVector, but on iOS it is defined through FVectorWorkaround. And if you try to read the scene, it crashes. I’ve replaced the property by FVector3d) I hope it will help someone.