# Metahuman crashes when I'm compiling identity **URL:** \ **Category:** Issues and Bug Reporting\ **Tags:** unreal-engine, bug-report, question, metahuman\ **Created:** [May 15, 2025, 3:22pm UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644 "2025-05-15T15:22:49Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![heyyidontcare](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@heyyidontcare](https://forums.unrealengine.com/u/heyyidontcare)\ **Post date:** [May 15, 2025, 3:22pm UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/1 "2025-05-15T15:22:50Z")
### Summary My unreal version is 5.6, it’s crashes with error “The package to load does not exist on disk or in the loader” and "Error: appError called: Assertion failed: IsThisNotNull(this, “UStruct::IsChildOf”) [File:D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\Class.cpp] [Line: 2743] " ### Please select what you are reporting on: Creative ### What Type of Bug are you experiencing? Character ### Steps to Reproduce 1. Make new metahuman character 2. Compile him ### Expected Result It should compily my metahuman character for work ### Observed Result It’s crashes Unreal ### Platform(s) Windows ---
**Author:** ![rymdskeppet](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/rymdskeppet/32/88715_2.png) [@rymdskeppet](https://forums.unrealengine.com/u/rymdskeppet)\ **Post date:** [June 8, 2025, 9:46am UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/2 "2025-06-08T09:46:58Z")
I get the same issue when I try to build/cook my game. I don’t use this `IsChildOf` function in my codebase and it’s rather hard to track down where the issue lies. ---
**Author:** ![EddieChristian](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@EddieChristian](https://forums.unrealengine.com/u/EddieChristian)\ **Post date:** [June 11, 2025, 1:10am UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/3 "2025-06-11T01:10:08Z")
Yep confirmed this on PC Windows. Can’t build with Metahumans plugins activated. ---
**Author:** ![rymdskeppet](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/rymdskeppet/32/88715_2.png) [@rymdskeppet](https://forums.unrealengine.com/u/rymdskeppet)\ **Post date:** [August 5, 2025, 12:56pm UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/4 "2025-08-05T12:56:46Z")
This was mentioned in the 5.6 release thread + a possible workaround: [Unreal Engine 5.6 Released - #119 by unit23](https://forums.unrealengine.com/t/unreal-engine-5-6-released/2538952/119) ---
**Author:** ![WeberSystems](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/webersystems/32/1216362_2.png) [@WeberSystems](https://forums.unrealengine.com/u/WeberSystems)\ **Post date:** [August 17, 2025, 11:32pm UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/5 "2025-08-17T23:32:14Z")
Exactly the same issue with my RPG Engine project. After making some changes (removed unnecessary data assets), this error appeared: Assertion failed: IsThisNotNull(this, “UStruct::IsChildOf”) [File:D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\Class.cpp] [Line: 2758] ---
**Author:** ![rymdskeppet](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/rymdskeppet/32/88715_2.png) [@rymdskeppet](https://forums.unrealengine.com/u/rymdskeppet)\ **Post date:** [September 13, 2025, 8:13am UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/6 "2025-09-13T08:13:19Z")
Another mention here regarding this issue: [https://forums.unrealengine.com/t/unreal-engine-5-6-released/2538952/300](https://forums.unrealengine.com/t/unreal-engine-5-6-released/2538952/300) ---
**Author:** ![CHADALAK1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@CHADALAK1](https://forums.unrealengine.com/u/CHADALAK1)\ **Post date:** [September 17, 2025, 6:36am UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/7 "2025-09-17T06:36:49Z")
Considering my post [here](https://forums.unrealengine.com/t/unreal-engine-5-6-released/2538952/300), I did have the MetaHuman plug-in enabled. Looks like the cook is about to succeed here with it turned off. I’ll do more and check in on this to confirm on my end too. Then again, looking at the MetaHuman plug-in’s content blueprints, funnily enough, there’s a lot of busted blueprints 🫠 . Was it this way as well in 5.6.0? Would love to use the MetaHuman plug-in but if it’s at the cost of a 1 out of 10 build succeeding, I would deal with the former 😕 . ---
**Author:** ![CHADALAK1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@CHADALAK1](https://forums.unrealengine.com/u/CHADALAK1)\ **Post date:** [September 17, 2025, 7:05am UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/8 "2025-09-17T07:05:41Z")
Responding to my post here. I guess it’s not necessarily the MetaHuman plug-in. It successfully build after disabling it. However, it failed when I attempted to package build again sadly. I did make a post here that seems very consistent to actually making builds work (if you’re in the Unreal Source Discord server . check [here](https://discord.com/channels/187217643009212416/402958499660955658/1417751557134352456) if you wanna see the post), but yea it seems I have to deleted the DerivedDataCache, Binaries, Intermediate and Saved folder after every single build in order for the builds to succeed consistently with 5.6.1 . It’s a weeiiirrrdd phenomena, but 🤷 I really don’t know a better solution to this unless Epic can resolve this issue. ---
**Author:** ![system](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/3/713c9d3f58553f0de89543d76a8a3a2779dc9fa4.png) [@system](https://forums.unrealengine.com/u/system)\ **Post date:** [November 11, 2025, 3:22pm UTC](https://forums.unrealengine.com/t/metahuman-crashes-when-im-compiling-identity/2511644/9 "2025-11-11T15:22:49Z")
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