Niagara Systems + Make new from User parameter = Assertion failed

Development Asset Creation FX
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1

Engine version: 4.25.1
OS: Windows 10 (64)
GPU: Nvideo
Driver: Studio version

I’m currently experiencing difficulty with Niagara and the “Make new from User parameter” option. Whenever, I try to add a user parameter the engine crashes with the error message below.

Error message

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4+Licensee\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 674] Array index out of bounds: 0 from an array of size 0

UE4Editor_Core
UE4Editor_Core
UE4Editor_Niagara
UE4Editor_Niagara
UE4Editor_NiagaraEditor
UE4Editor_NiagaraEditor
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll

Things I have tried.

  1. Created a new Niagara System added a Niagara Emitter. (still same problem)
  2. Paused all active systems and emitters and tried again. (still same problem)
  3. Created a new Niagara System/Emitters - duplicated and renamed them and tried again. (still same problem)

304830-user-param-crash.jpg
304830-user-param-crash.jpg1330×854 200 KB

2

Same problem here. Steps to get that error are reproducable on clear project and default Emitter/System from it. Setting ANY value to read from new User parameter leads to crash.
Epic pls fix

3

Same here.

4

■■■■, same issue here

5

Exact same issue here, any ETA on a possible fix?

6

Yes, this works. I experienced crashes as well when trying to create a new user variable by selecting Read From New User Parameter. But if you create a new variable by hand and then just drag it to where you want to use it, everything’s fine.

7

You can create a user variable in the left part of the NS editor (parameters → user exposed) and then use it in your emitter

8

That’s a good workaround while this gets fixed, thank you!

9

Thanks worked for me as well. Used a Youtube tutorial though… noob. Need the tutorial, See “UE4 - Niagara Blueprints and User Parameters” by GameDev Outpost at 2:15.

10

I am having a similar problem. though my computer doesn’t crash if i for example make a user parameter for the lifetime the particle will disappear but if i reset the lifetime and then drag the parameter i just made from the User Exposed menu it works again.

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