# Playground error "TypeScript not registered"
**URL:** https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445
**Category:** Bugs
**Created:** [November 20, 2021, 1:38am UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445 "2021-11-20T01:38:15Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Blake](https://forum.babylonjs.com/u/Blake)
#### Post date: [November 20, 2021, 1:38am UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/1 "2021-11-20T01:38:15Z")
Heya, I came across an issue where if a TypeScript playground link is opened in a browser where JavaScript was last used in the playground, then there’s the error “TypeScript not registered” and the page fails to load. However if TypeScript was the last language used in the playground then it loads fine.
```auto
babylon.playground.js:16 TypeScript not registered!
```
To reproduce it, save the default TypeScript playground, switch to JavaScript, hit reload and it fails. Or if you were in JavaScript the last time you visited the playground with your current device and browser, then the error can be reproduced by clicking on any TypeScript playground link, such as below.
[https://playground.babylonjs.com/#P67T34](https://playground.babylonjs.com/#P67T34)
---
### Author:  [@sebavan](https://forum.babylonjs.com/u/sebavan)
#### Post date: [November 20, 2021, 1:48am UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/2 "2021-11-20T01:48:30Z")
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### Author:  [@sebavan](https://forum.babylonjs.com/u/sebavan)
#### Post date: [November 20, 2021, 1:48am UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/3 "2021-11-20T01:48:56Z")
@RaananW might have an idea 🙂
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### Author:  [@RaananW](https://forum.babylonjs.com/u/RaananW)
#### Post date: [November 22, 2021, 12:41pm UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/4 "2021-11-22T12:41:48Z")
i can reproduce that, i’ll check what happened.
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### Author:  [@Deltakosh](https://forum.babylonjs.com/u/Deltakosh)
#### Post date: [November 29, 2021, 4:00pm UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/5 "2021-11-29T16:00:27Z")
Any news @RaananW ?
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### Author:  [@RaananW](https://forum.babylonjs.com/u/RaananW)
#### Post date: [November 29, 2021, 4:05pm UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/6 "2021-11-29T16:05:04Z")
Sorry, delayed this one a bit.
I’ll fix that later today or tomorrow.
---
### Author:  [@RaananW](https://forum.babylonjs.com/u/RaananW)
#### Post date: [November 30, 2021, 6:11pm UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/7 "2021-11-30T18:11:36Z")
This issue is resolved with this PR:
[Playground - Typescript is not registered issue by RaananW · Pull Request #11554 · BabylonJS/Babylon.js (github.com)](https://github.com/BabylonJS/Babylon.js/pull/11554)
---
### Author:  [@RaananW](https://forum.babylonjs.com/u/RaananW)
#### Post date: [November 30, 2021, 6:18pm UTC](https://forum.babylonjs.com/t/playground-error-typescript-not-registered/25445/8 "2021-11-30T18:18:47Z")