# Transions samples do not play, error: "Programmer sound callback is not set for instrument" (solved)

**URL:** <https://qa.fmod.com/t/transions-samples-do-not-play-error-programmer-sound-callback-is-not-set-for-instrument-solved/22117>\
**Category:** Unreal Engine\
**Tags:** blueprints, ue5\
**Created:** [September 23, 2024, 12:10pm UTC](https://qa.fmod.com/t/transions-samples-do-not-play-error-programmer-sound-callback-is-not-set-for-instrument-solved/22117 "2024-09-23T12:10:26Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dreamofgold](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@dreamofgold](https://qa.fmod.com/u/dreamofgold)\
**Post date:** [September 23, 2024, 12:10pm UTC](https://qa.fmod.com/t/transions-samples-do-not-play-error-programmer-sound-callback-is-not-set-for-instrument-solved/22117/1 "2024-09-23T12:10:26Z")

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Hello everyone!  
I am quite a new to UE and FMOD, and i’ve got a problem I dont have any idea to solve ☹  
Basically, I have some event, create and build in fmod which I am testing in UE using box colliders to trigger changing parameter value and see all transions work fine:

 ![image](https://canada1.discourse-cdn.com/flex036/uploads/fmod/original/2X/e/eb34d9ab14fb58bb5b4c05b7816b14fbebddf5ea.jpeg)

the problem is highlighted transion - it has 2 samples, only one of them have to be played based on the parameter value (TransitionInSpeed).  
It works perfectly in fmod, it reacts on paramter value, it playes correct sample.  
In UE I created simple blueprint to check how transiotion works based on TensionLevel parameter values.  
I have 2 boxes:

- box1 is big one - if I am outside - TensionLevel is 2 and plays specific music
- if I am inside box1 - TensionLevel is 1 and plays different music

between this 2 changes have to be played some transions samples I set.

The problem is that transition samples (highlighted higher) do not play when i switch between values 1 → 2 for tensionLevel, when I go ount of box1, in console i see error:

LogFMOD: Warning: C:\buildagent1\work\570ad728b1678096\studio\_api\src\fmod\_shadow\_event.cpp(361) - Programmer sound callback is not set for instrument ‘’.  
LogFMOD: Warning: C:\buildagent1\work\570ad728b1678096\studio\_api\src\fmod\_playback\_event.cpp(2267) - Programmer sound callback for instrument ‘’ returned no sound.

All other music and samples plays just fine and I can’t get what’s wrong with theese 2 specific samples or transition at all.

Can anyone give a hint or advice - what should I check and fix?

Thanks.

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<div class="post-metadata">

**Author:** ![dreamofgold](https://avatars.discourse-cdn.com/v4/letter/d/9dc877/32.png) [@dreamofgold](https://qa.fmod.com/u/dreamofgold)\
**Post date:** [September 23, 2024, 12:23pm UTC](https://qa.fmod.com/t/transions-samples-do-not-play-error-programmer-sound-callback-is-not-set-for-instrument-solved/22117/2 "2024-09-23T12:23:41Z")

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Good thoughts comes after good questions 🙂  
The problem was that I used programmer instruments for transitions samples.  
I dont really understand, why they did not work properly, cus there were set samples for programmer track and they wokr in FMOD.

Any way, I solved this problem by deleting programmer instruments and drag-n-droping samples from assets into timeline and setting their conditions.

May be will be helpful for anyone.