# UE5 Crash On Load - Parameter LFO automation with another LFO

**URL:** <https://qa.fmod.com/t/ue5-crash-on-load-parameter-lfo-automation-with-another-lfo/19451>\
**Category:** Unreal Engine\
**Created:** [October 27, 2022, 9:22pm UTC](https://qa.fmod.com/t/ue5-crash-on-load-parameter-lfo-automation-with-another-lfo/19451 "2022-10-27T21:22:26Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![AphoticRazor](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/aphoticrazor/32/2082_2.png) [@AphoticRazor](https://qa.fmod.com/u/AphoticRazor)\
**Post date:** [October 27, 2022, 9:22pm UTC](https://qa.fmod.com/t/ue5-crash-on-load-parameter-lfo-automation-with-another-lfo/19451/1 "2022-10-27T21:22:26Z")

</div>

Hello,

I have an event for characters speaking and want to randomize it so the person speaking changes at varied intervals, and then use a parameter to control the random rate in-engine.

My implementation for this is as so…

1. The voices are triggered as multi-instruments in a labeled parameter sheet “VOXSwitch” (so I can use AHDSR to fade them out when they switch).
2. VOXSwitch is modulated with a LFO to switch between voices.
3. The rate of that LFO is automated by param “Random” using a random ramp LFO.
4. The Random LFO rate/direction is automated with a continuous param “VOXRate” to change the random rate via in-engine parameters.

It works fine in Studio, but after building banks and opening UE5 it crashes. The final error in the UE crash log is…

> Error: c:\jk\workspace\Build\_\_2.2\_\_Unreal\_Win\studio\_api\src\fmod\_model\_base.h(38) - assertion: ‘mMagic == MAGIC\_WORD’ failed

It also causes Studio to crash after closing Studio.

I tested this issue a few times and the cause always seems to be when you automate a parameter LFO with another parameter using LFO modulation, regardless of seek speed.

Software versions tested:  
FMOD 2.02.08  
FMOD 2.02.09  
Unreal Engine 5.0.3

---

<div class="post-metadata">

**Author:** ![Connor\_FMOD](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/connor_fmod/32/3685_2.png) [@Connor\_FMOD](https://qa.fmod.com/u/Connor_FMOD)\
**Post date:** [November 3, 2022, 5:52am UTC](https://qa.fmod.com/t/ue5-crash-on-load-parameter-lfo-automation-with-another-lfo/19451/2 "2022-11-03T05:52:18Z")

</div>

Hi,

Is it possible to upload your FMOD project to your profile to test on my end?