# Problems building v4 into an existing JS library

**URL:** <https://forum.deepar.ai/t/problems-building-v4-into-an-existing-js-library/105>\
**Category:** Help & Questions\
**Created:** [September 27, 2022, 8:40pm UTC](https://forum.deepar.ai/t/problems-building-v4-into-an-existing-js-library/105 "2022-09-27T20:40:42Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![jelena](https://dub1.discourse-cdn.com/flex017/user_avatar/forum.deepar.ai/jelena/32/14_2.png) [@jelena](https://forum.deepar.ai/u/jelena)\
**Post date:** [September 28, 2022, 12:07pm UTC](https://forum.deepar.ai/t/problems-building-v4-into-an-existing-js-library/105/2 "2022-09-28T12:07:26Z")

</div>

HI @chadbailey,

The troubleshooting steps described in this thread

> [@Web SDK Memory Out Of Bounds exception](https://forum.deepar.ai/t/web-sdk-memory-out-of-bounds-exception/31):
>
> If you get this error while using DeepAR on your domain, you should check the metadata header settings (Content-Encoding and Content-Type) for .js, .wasm, model and effect files on your server. These are explained in the [getting started guide](https://docs.deepar.ai/deepar-sdk/deep-ar-sdk-for-web/getting-started) You can also Inspect your page and compare the metadata headers to one of our [demo examples](https://sdk.developer.deepar.ai/virtualTryOn/index.html). This should make it any mismatches easier to spot.

Refer specifically to errors that happen when serving DeepAR on a domain, that don’t show up when serving locally. I would recommend going through those steps first, especially comparing your content type and content encoding to our examples.

---

_[View the full topic](https://forum.deepar.ai/t/problems-building-v4-into-an-existing-js-library/105)._