# \[4.15\] Issues with Map Build Data

**URL:** <https://forums.unrealengine.com/t/4-15-issues-with-map-build-data/392787>\
**Category:** Rendering\
**Tags:** UE4-15, unreal-engine, Lighting, question\
**Created:** [May 5, 2017, 10:11am UTC](https://forums.unrealengine.com/t/4-15-issues-with-map-build-data/392787 "2017-05-05T10:11:23Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Darxen](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Darxen](https://forums.unrealengine.com/u/Darxen)\
**Post date:** [May 5, 2017, 10:11am UTC](https://forums.unrealengine.com/t/4-15-issues-with-map-build-data/392787/1 "2017-05-05T10:11:23Z")

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Hi,  
I’m having issues with Map Build Data file and level streaming.

We are using a master level that cointains all the existing levels, so what we do is to show and hide the levels depending on what point of the game the player is.  
The light is being built inside each “sublevel”. But there’s one level that is not loading correctly, the light showed in the master level doesn’t match with the light showed inside the sublevel. I have no idea why is this happening… I think maybe is something about that new file “BuiltData” that is not being loaded correctly or something like that, because each time I load the master level, it says “failed to import for MapBuildDataRegistry”, referencing to the sublevel BuiltData.  
In fact, all the light data from the sublevel has gone and I have to build lights… again…

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**Author:** ![Darxen](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Darxen](https://forums.unrealengine.com/u/Darxen)\
**Post date:** [May 9, 2017, 12:12pm UTC](https://forums.unrealengine.com/t/4-15-issues-with-map-build-data/392787/2 "2017-05-09T12:12:27Z")

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No one knows what’s happening?

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**Author:** ![anonymous\_user\_6e7b421a](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_6e7b421a](https://forums.unrealengine.com/u/anonymous_user_6e7b421a)\
**Post date:** [May 10, 2017, 5:09pm UTC](https://forums.unrealengine.com/t/4-15-issues-with-map-build-data/392787/3 "2017-05-10T17:09:06Z")

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Hey Darxen,

Would happen to have a steps for me to reproduce this issue on my end?

I did find a couple of known issues regarding the Map Build Data registry/asset. Read over the two bugs provided in the links below and let me know if you think your issue pertains to one or both.

**[UE-44197](https://issues.unrealengine.com/issue/UE-44197)**

**[UE-37030](https://issues.unrealengine.com/issue/UE-37030)**

Let me know if you have additional questions.

Thank you,

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**Author:** ![Darxen](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Darxen](https://forums.unrealengine.com/u/Darxen)\
**Post date:** [May 10, 2017, 9:31pm UTC](https://forums.unrealengine.com/t/4-15-issues-with-map-build-data/392787/4 "2017-05-10T21:31:11Z")

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Yes, sorry for not updating.

It was the UE-44197 issue. It’s solved.

Thank you so much.