# Master.string is not a vaild bank

**URL:** <https://qa.fmod.com/t/master-string-is-not-a-vaild-bank/20654>\
**Category:** FMOD Studio\
**Created:** [September 14, 2023, 2:49pm UTC](https://qa.fmod.com/t/master-string-is-not-a-vaild-bank/20654 "2023-09-14T14:49:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![DeanKR](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@DeanKR](https://qa.fmod.com/u/DeanKR)\
**Post date:** [September 14, 2023, 2:49pm UTC](https://qa.fmod.com/t/master-string-is-not-a-vaild-bank/20654/1 "2023-09-14T14:49:45Z")

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So I have this error I have seen around here already, but none of the solutions seems to be relevant.  
I have the proper Fmod and Unity version, and everything seemed to work just fine.

This is a project I joined after Fmod was integrated, and I managed to set up the music already and implement it.  
Now I added all of my SFX and built the mixer and the error started.  
Any ideas on what I can do here?

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**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:** [September 15, 2023, 6:38am UTC](https://qa.fmod.com/t/master-string-is-not-a-vaild-bank/20654/2 "2023-09-15T06:38:42Z")

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Hi,

What version of FMOD and Unity are you using?

With the Unity integration set to ([Warning` Unity Integration | Settings - Logging Level](https://fmod.com/docs/2.02/unity/settings.html#logging-level)) please upload any logs that you are seeing with FMOD errors.

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<div class="post-metadata">

**Author:** ![DeanKR](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@DeanKR](https://qa.fmod.com/u/DeanKR)\
**Post date:** [September 15, 2023, 9:45am UTC](https://qa.fmod.com/t/master-string-is-not-a-vaild-bank/20654/3 "2023-09-15T09:45:32Z")

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Hi Connor thank you for the reply!

I am using Fmod 2.02.15 and Unity 2020.3.45f1. The text is red so I assume it’s a warning? if it collerates with Unity’s logic.

Anyway, yesterday the problem got fixed, I have no idea how, tons of attempts to mess around with builds, manual deletion of banks, and old branch pulling and pushing.

Today it happened again, and I think I got a better sense of how to fix it -  
I deleted the banks manually and built them while Unity was not open.  
Then I closed Fmod and opened Unity, and Unity gave me a notification that “some files were changed” or something similar.  
After that, the Master.string not valid problem was gone and I am able to build banks normally.

I still did not properly solve it though, I believe it will happen again.  
The main two common things between today and yesterday are that the problem started **after** I added new assets and assigned them to banks and mixer groups,

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<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:** [September 17, 2023, 10:56pm UTC](https://qa.fmod.com/t/master-string-is-not-a-vaild-bank/20654/4 "2023-09-17T22:56:17Z")

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Hi,

In the integration settings, what do you have the [Unity Integration | Settings - Source Type](https://fmod.com/docs/2.02/unity/settings.html#source-type) set as? If you change the source to `Single Build` do you still experience the error? It is interesting that it is coming and going. If you update to the latest Unity Verified version `2.02.17` do you still experience the issue?