# 4.9.2 USTRUCTs doesn't hot reload. Causes saving and compilation errors

**URL:** <https://forums.unrealengine.com/t/4-9-2-ustructs-doesnt-hot-reload-causes-saving-and-compilation-errors/339788>\
**Category:** Editor Scripting\
**Tags:** ustruct, compilation-error, unreal-engine, question, hot-reload\
**Created:** [November 26, 2015, 9:05pm UTC](https://forums.unrealengine.com/t/4-9-2-ustructs-doesnt-hot-reload-causes-saving-and-compilation-errors/339788 "2015-11-26T21:05:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![BujakD](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@BujakD](https://forums.unrealengine.com/u/BujakD)\
**Post date:** [November 26, 2015, 9:05pm UTC](https://forums.unrealengine.com/t/4-9-2-ustructs-doesnt-hot-reload-causes-saving-and-compilation-errors/339788/1 "2015-11-26T21:05:21Z")

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Hi,

repro steps:

1. Create new C++ project out of Blank template, dont add starter content

2. When new project launches and Editor opens go to AddNew-\>New C++ Class. Add new class derived from Actor, name it MyActor

3. Open MyActor.h in VS, add this code before class definition:

4. In class AMyActor add new member:

5. Compile project by hitting compile button in EDITOR (!) main tab

6. After hot reload create new blueprint, inherit it from MyActor. Name it NewBlueprint

7. Open new blueprint, in event graph add this network:  
68364-

8. Compile blueprint

8)Go to MyActor.h in VS, add this code to Fmystruct:

```
	UPROPERTY(BlueprintReadWrite, EditAnywhere)
		int32 myint2;

```

1. Go to enreal editor and hit compile button.

2. When game hot reloads open NewBlueprint. Try to save. You will get error message. Try to compile, compilation may or may not be successfull. Notice that “break mystruct” node did not update to match current Fmystruct state

 ![68365-errormsgwhensave.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/6/3/863cc9412835a36fd4c9a3f82d5f7af52bee0492.png)

---

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**Author:** ![Sean\_Flint](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Sean\_Flint](https://forums.unrealengine.com/u/Sean_Flint)\
**Post date:** [November 27, 2015, 7:23pm UTC](https://forums.unrealengine.com/t/4-9-2-ustructs-doesnt-hot-reload-causes-saving-and-compilation-errors/339788/2 "2015-11-27T19:23:40Z")

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Hello,

This is a known issue (UE-21554) and will be fixed in a future version of the engine. Thank you for your report. For now, I would recommend building through Visual Studio, as there are some issues that relate specifically to the in-editor compile button that are currently being investigated.

Have a great day,

Sean Flint