# Android arm64 build failing preview 4.25 vers7

**URL:** <https://forums.unrealengine.com/t/android-arm64-build-failing-preview-4-25-vers7/463888>\
**Category:** Mobile\
**Tags:** error, build, unreal-engine, fail, Android, question\
**Created:** [April 17, 2020, 12:33pm UTC](https://forums.unrealengine.com/t/android-arm64-build-failing-preview-4-25-vers7/463888 "2020-04-17T12:33:42Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![pop-eye](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@pop-eye](https://forums.unrealengine.com/u/pop-eye)\
**Post date:** [April 17, 2020, 12:33pm UTC](https://forums.unrealengine.com/t/android-arm64-build-failing-preview-4-25-vers7/463888/1 "2020-04-17T12:33:42Z")

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Followed these instructions for installing NDK-21 for 4.25:

> **[Updates to required setup for Android NDK 21 in Unreal Engine 4.25](https://www.unrealengine.com/en-US/tech-blog/updates-to-required-setup-for-android-ndk-21-in-unreal-engine-4-25)**
>
> We are updating Unreal Engine 4.25 to use Android NDK r21. In this post, we will walk you through the new setup process that Android developers will need to take advantage of the update.

However with blank project arm64 android .aab build I get the attached errors and build fails, same on another device what am I missing?

Log attached mainly errors similar to “ld.lld: error: undefined symbol: FMemory::Malloc(unsigned long long, unsigned int)”

Thanks in advance!

link text

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<div class="post-metadata">

**Author:** ![pop-eye](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@pop-eye](https://forums.unrealengine.com/u/pop-eye)\
**Post date:** [April 17, 2020, 1:20pm UTC](https://forums.unrealengine.com/t/android-arm64-build-failing-preview-4-25-vers7/463888/2 "2020-04-17T13:20:18Z")

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armv7 does compile successfully, but still same errors with arm64.

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**Author:** ![JayChang-zhe](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@JayChang-zhe](https://forums.unrealengine.com/u/JayChang-zhe)\
**Post date:** [February 26, 2021, 7:40am UTC](https://forums.unrealengine.com/t/android-arm64-build-failing-preview-4-25-vers7/463888/3 "2021-02-26T07:40:53Z")

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So what’s going on in the end ?