# Unreal Engine 5.6 Released

**URL:** <https://forums.unrealengine.com/t/unreal-engine-5-6-released/2538952>\
**Category:** Announcements\
**Tags:** unreal-engine, Released\
**Created:** [June 3, 2025, 1:50pm UTC](https://forums.unrealengine.com/t/unreal-engine-5-6-released/2538952 "2025-06-03T13:50:06Z")\
**Posts on this page:** 1\
**Showing post:** 119

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**Author:** ![unit23](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/unit23/32/1146013_2.png) [@unit23](https://forums.unrealengine.com/u/unit23)\
**Post date:** [June 16, 2025, 3:55pm UTC](https://forums.unrealengine.com/t/unreal-engine-5-6-released/2538952/119 "2025-06-16T15:55:28Z")

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When building the 5.6 source build getting this error:

> PackagingResults: Warning: ‘UStruct::IsChildOf’ was called with a null ‘this’ pointer - this is no longer supported.  
> UATHelper: Packaging (Windows): LogWindows: Error: appError called: Assertion failed: IsThisNotNull(this, “UStruct::IsChildOf”) [File:D:\Engine\UE\_5.6\_Source\Engine\Source\Runtime\CoreUObject\Private\UObject\Class.cpp] [Line: 2751]  
> PackagingResults: Error: appError called: Assertion failed: IsThisNotNull(this, “UStruct::IsChildOf”) [File:D:\Engine\UE\_5.6\_Source\Engine\Source\Runtime\CoreUObject\Private\UObject\Class.cpp] [Line: 2751]

Any thoughts?

Similar error when building with the 5.5 Strider plug-in (successfully compiled), resulting in **unknown structure** errors. Above error is printed on build completion without other log errors ( mentioned plug-in removed).

**UPDATE 1**  
When compiling 5.6 default, this error on build completion

> Unhandled Exception: EXCEPTION\_ACCESS\_VIOLATION reading address 0x0000000000000008

**UPDATE 2**  
Turns out this is probably just a case of corrupted structures, which can be fixed by opening and saving affected files and or the related structures. But there is a chance that this is a bug.

**Summary**  
When structure errors are present in a 5.5 project and the project is upgraded to 5.6, the specific files with the structure corruptions are not printed in the output log. The question is if structure errors created in a 5.6 release are displayed in the log.

**UPDATE** February 2026 [Unreal Engine 5.7 Released - #197 by unit23](https://forums.unrealengine.com/t/unreal-engine-5-7-released/2673913/197)

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