# Sample code downloaded from Playground will result in an error **URL:** \ **Category:** Bugs\ **Created:** [December 7, 2020, 6:03pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401 "2020-12-07T18:03:58Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![cx20](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/cx20/32/46_2.png) [@cx20](https://forum.babylonjs.com/u/cx20)\ **Post date:** [December 7, 2020, 6:03pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/1 "2020-12-07T18:03:58Z")
I tried to download the sample code from Babylon.js Playground. However, I get an error when I try to do it. The following is the reproduction procedure. 1. Goto Babylon.js Playground [https://playground.babylonjs.com/](https://playground.babylonjs.com/) 2. Download sample.zip ![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/2X/d/db07a932b7eb87fcf75b6b1972041cff4386d000.png) 3. Unzip sample.zip 4. Start a local server and access the sample URL. The following error occurs and the sample is not displayed. ```auto Uncaught TypeError: Cannot read property 'runRenderLoop' of null ``` Probably because the `initFunction` is not called. ---
**Author:** ![Deltakosh](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/deltakosh/32/26635_2.png) [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)\ **Post date:** [December 7, 2020, 6:47pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/2 "2020-12-07T18:47:01Z")
Correct! I forgot to fix that thanks a lot, I will make that work ---
**Author:** ![cx20](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/cx20/32/46_2.png) [@cx20](https://forum.babylonjs.com/u/cx20)\ **Post date:** [December 7, 2020, 6:49pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/3 "2020-12-07T18:49:12Z")
BTW, it would be nice to be able to switch to WebGPU as well. ---
**Author:** ![Deltakosh](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/deltakosh/32/26635_2.png) [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)\ **Post date:** [December 7, 2020, 6:49pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/4 "2020-12-07T18:49:48Z")
You can already in the PG but I do not plan to support it in the downloadable one (yet) I mean: the downloadable version will use the same engine as the one active when you hit save ---
**Author:** ![cx20](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/cx20/32/46_2.png) [@cx20](https://forum.babylonjs.com/u/cx20)\ **Post date:** [December 7, 2020, 6:56pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/5 "2020-12-07T18:56:08Z")
It’s not necessary to be able to download it, but it would be nice to be able to test it easily on Playground. The following WebGPU documentation has a link to Playground. > **[WebGPU Support | Babylon.js Documentation](https://doc.babylonjs.com/advanced_topics/webGPU)** > > Dive into understanding the full scope of support for WebGPU in Babylon.js. ---
**Author:** ![Deltakosh](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/deltakosh/32/26635_2.png) [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)\ **Post date:** [December 7, 2020, 7:02pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/6 "2020-12-07T19:02:12Z")
it is already working 🙂 ![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/2X/f/fc1a87c46234492d207639da98746dd14c2a4108.png) Pinging @PirateJC for the doc update ---
**Author:** ![cx20](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/cx20/32/46_2.png) [@cx20](https://forum.babylonjs.com/u/cx20)\ **Post date:** [December 7, 2020, 7:05pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/7 "2020-12-07T19:05:24Z")
Oops, just noticed it. Great job. ---
**Author:** ![PirateJC](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/piratejc/32/1003_2.png) [@PirateJC](https://forum.babylonjs.com/u/PirateJC)\ **Post date:** [December 7, 2020, 9:36pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/8 "2020-12-07T21:36:15Z")
Doc has been updated. Will go into the next PR within the next couple hours ---
**Author:** ![cx20](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/cx20/32/46_2.png) [@cx20](https://forum.babylonjs.com/u/cx20)\ **Post date:** [December 7, 2020, 11:57pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/9 "2020-12-07T23:57:14Z")
Thank you for your quick fix. I have confirmed that the correct sample code can be downloaded for each mode of WebGPU / WebGL2. WebGPU mode result: ![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/2X/f/f4c3b31a91fda4d469c583493cd902a2eadc2a45.png) WebGL2 mode result: ![image](https://us1.discourse-cdn.com/flex024/uploads/babylonjs/original/2X/5/52bbceafbd1360b3dad6eb8a5be49354e5d99931.png) ---
**Author:** ![cx20](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/cx20/32/46_2.png) [@cx20](https://forum.babylonjs.com/u/cx20)\ **Post date:** [December 7, 2020, 11:59pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/10 "2020-12-07T23:59:50Z")
Sorry if this has already been addressed. I found another mistake. The following URLs seem to refer to an old library (Babylon.js v4.2.0-alpha.16 or 27) ``` https://playground.babylonjs.com/indexWebGPU.html https://www.babylonjs.com/demos/webgpu/forestwebgpu https://www.babylonjs.com/demos/webgpu/oneSphereWebGPU https://www.babylonjs.com/demos/webgpu/oneHelmetWebGPU https://www.babylonjs.com/demos/webgpu/tenThousandSpheresWebGPU ``` ---
**Author:** ![Deltakosh](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/deltakosh/32/26635_2.png) [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)\ **Post date:** [December 8, 2020, 10:04pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/11 "2020-12-08T22:04:49Z")
cc @Evgeni_Popov ---
**Author:** ![cx20](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/cx20/32/46_2.png) [@cx20](https://forum.babylonjs.com/u/cx20)\ **Post date:** [December 8, 2020, 10:44pm UTC](https://forum.babylonjs.com/t/sample-code-downloaded-from-playground-will-result-in-an-error/16401/12 "2020-12-08T22:44:30Z")
Thank you for catching up. The last one is already posted in another thread. > [@Some WebGPU samples refer to older versions of the engine](https://forum.babylonjs.com/t/some-webgpu-samples-refer-to-older-versions-of-the-engine/16429): > > The following URLs seem to refer to an old library (Babylon.js v4.2.0-alpha.16 or 27) https://playground.babylonjs.com/indexWebGPU.html https://www.babylonjs.com/demos/webgpu/forestwebgpu https://www.babylonjs.com/demos/webgpu/oneSphereWebGPU https://www.babylonjs.com/demos/webgpu/oneHelmetWebGPU https://www.babylonjs.com/demos/webgpu/tenThousandSpheresWebGPU Some of these samples are referenced from the WebGPU Wiki. [image]