# Build time increased ~10x when migrating from 5.5 to 5.6 

**URL:** <https://forums.unrealengine.com/t/build-time-increased-10x-when-migrating-from-5-5-to-5-6/2571374>\
**Category:** Programming & Scripting\
**Tags:** build, unreal-engine, CPP, question\
**Created:** [June 22, 2025, 10:31pm UTC](https://forums.unrealengine.com/t/build-time-increased-10x-when-migrating-from-5-5-to-5-6/2571374 "2025-06-22T22:31:15Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![BartyTurbo1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@BartyTurbo1](https://forums.unrealengine.com/u/BartyTurbo1)\
**Post date:** [June 24, 2025, 10:46am UTC](https://forums.unrealengine.com/t/build-time-increased-10x-when-migrating-from-5-5-to-5-6/2571374/4 "2025-06-24T10:46:19Z")

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Ah, after digging a bit through the buildconfiguration apparently in Unreal 5.6 the UBAExecutor is now **enabled by default** , where it was **disabled** by default in 5.5.

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/8/c/68c55a2f975815e60c1f03f078764d5c3e29e9c6.png)

After manually disabling it I’m getting back to my old compilation speed of ~90 seconds instead of 10min.

For anyone encountering the same problem, edit your BuildConfiguration.xml to this:

```auto
<?xml version="1.0" encoding="utf-8" ?>
<Configuration xmlns="https://www.unrealengine.com/BuildConfiguration">
	<BuildConfiguration>
		<bAllowUBAExecutor>false</bAllowUBAExecutor>
	</BuildConfiguration>
</Configuration>

```

Bit strange why this change in default behavior wasn’t in the patch notes. 🤔

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