# Cooked pak thread-specific archive error (4.15.1)

**URL:** <https://qa.fmod.com/t/cooked-pak-thread-specific-archive-error-4-15-1/13151>\
**Category:** Unreal Engine\
**Created:** [May 2, 2017, 5:27am UTC](https://qa.fmod.com/t/cooked-pak-thread-specific-archive-error-4-15-1/13151 "2017-05-02T05:27:59Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![thejustinwalsh](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@thejustinwalsh](https://qa.fmod.com/u/thejustinwalsh)\
**Post date:** [May 2, 2017, 5:27am UTC](https://qa.fmod.com/t/cooked-pak-thread-specific-archive-error-4-15-1/13151/1 "2017-05-02T05:27:59Z")

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We recently updated to UE 4.15.1 and I am seeing an error with how threads are accessing the content in a cooked packaged build. (When using PAK files specifically)

```auto
Attempted seek using thread-specific pak file reader on the wrong thread. Reader for thread 13828 used by thread 2124.
Attempted serialize using thread-specific pak file reader on the wrong thread. Reader for thread 13828 used by thread 2124.

```

From my initial research it looks like FMOD is loading the PAK file via`FMODOpen` on a Bank Loader thread. Then subsequently reading the archive via `FMODRead` from an FMOD file reader thread. I believe Unreal made loading changes in 4.15 that started logging an error when this occurs.

I am seeing this error with an accompanying random archive reading crash every once in a while when I make a cooked package using pak files in the development configuration. I had to attach to the cooked binary to trap the error since for whatever reason running it from VS was suppressing the error.

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**Author:** ![cameron-fmod](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/cameron-fmod/32/261_2.png) [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)\
**Post date:** [May 2, 2017, 6:15am UTC](https://qa.fmod.com/t/cooked-pak-thread-specific-archive-error-4-15-1/13151/2 "2017-05-02T06:15:37Z")

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Hi Justin,

Thank you for the bug report.

We are aware of this and are currently working on a solution.

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<div class="post-metadata">

**Author:** ![thejustinwalsh](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@thejustinwalsh](https://qa.fmod.com/u/thejustinwalsh)\
**Post date:** [May 2, 2017, 5:52pm UTC](https://qa.fmod.com/t/cooked-pak-thread-specific-archive-error-4-15-1/13151/3 "2017-05-02T17:52:08Z")

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> [@](#):
>
> Hi Justin,
> 
> Thank you for the bug report.
> 
> We are aware of this and are currently working on a solution.

Is there a workaround you would recommend or a rough ETA on a fix?

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<div class="post-metadata">

**Author:** ![cameron-fmod](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/cameron-fmod/32/261_2.png) [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)\
**Post date:** [May 3, 2017, 3:40am UTC](https://qa.fmod.com/t/cooked-pak-thread-specific-archive-error-4-15-1/13151/4 "2017-05-03T03:40:19Z")

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One work around is to not include the FMOD banks in the Pak file, by changing the FMOD folder to an “Additional Non-Asset Directory to Copy” instead of “Additional Non-Asset Directory to Package”.

We are hoping to have this completed fairly quickly, but it does involve overhauling our plugins file I/O system.