# Issue : \`PlayModeStateChange' could not be found. Are you missing an assembly reference?
**URL:** https://qa.fmod.com/t/issue-playmodestatechange-could-not-be-found-are-you-missing-an-assembly-reference/15127
**Category:** Unity
**Created:** [October 11, 2019, 10:35am UTC](https://qa.fmod.com/t/issue-playmodestatechange-could-not-be-found-are-you-missing-an-assembly-reference/15127 "2019-10-11T10:35:07Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@copu95](https://qa.fmod.com/u/copu95)
#### Post date: [October 11, 2019, 10:35am UTC](https://qa.fmod.com/t/issue-playmodestatechange-could-not-be-found-are-you-missing-an-assembly-reference/15127/1 "2019-10-11T10:35:07Z")
Unity version : 2017.1.0f3
FMOD version : 2.00.03
Trying to work on an old project but after importing the FMOD integration package i get.
> Blockquote Assets/Plugins/FMOD/src/Runtime/RuntimeManager.cs(609,40): error CS0246: The type or namespace name `PlayModeStateChange’ could not be found. Are you missing an assembly reference?
Opening the project in Unity 2017.3.1 and upwards fixes the integration issue but causes several other problems in the game that are beyond me.
Has anyone managed to fix this for Unity version : 2017.1.0f3 and integrate FMOD ?
The link below mentions changing " PlayModeStateChanged to PlaymodeStateChanged." , but i’m not sure where to do that exactly
- [Compiler Error after updating to newest version of MA | Dark Tonic Forum](http://darktonic.freeforums.net/thread/805/compiler-error-updating-newest-version)
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### Author:  [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)
#### Post date: [October 16, 2019, 4:30am UTC](https://qa.fmod.com/t/issue-playmodestatechange-could-not-be-found-are-you-missing-an-assembly-reference/15127/2 "2019-10-16T04:30:45Z")
[https://www.fmod.com/resources/documentation-unity?version=2.0&page=welcome.html#supported-unity-versions](https://www.fmod.com/resources/documentation-unity?version=2.0&page=welcome.html#supported-unity-versions)
> The Integration will work with all versions of Unity from 2017.4 onwards.
You can normally double click the error message in Unity and it will open the file with your IDE, otherwise you can find it in `Assets/Plugins/FMOD/src/Runtime/RuntimeManager.cs` line 609.