# Playground errors in Firefox **URL:** \ **Category:** Questions\ **Created:** [November 17, 2020, 9:05pm UTC](https://forum.babylonjs.com/t/playground-errors-in-firefox/15791 "2020-11-17T21:05:06Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![adam](https://avatars.discourse-cdn.com/v4/letter/a/4af34b/32.png) [@adam](https://forum.babylonjs.com/u/adam)\ **Post date:** [November 17, 2020, 9:05pm UTC](https://forum.babylonjs.com/t/playground-errors-in-firefox/15791/1 "2020-11-17T21:05:06Z")
Do these playgrounds work for others in Firefox? > **[Babylon.js Playground](https://playground.babylonjs.com/#P1RZV0)** [https://playground.babylonjs.com/#C21DGD#2](https://playground.babylonjs.com/#C21DGD#2) Im geting these errors: Uncaught (in promise) TypeError: BABYLON.NodeMaterial is undefined Uncaught (in promise) TypeError: BABYLON.AmmoJSPlugin is not a constructor ---
**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:** [November 17, 2020, 9:56pm UTC](https://forum.babylonjs.com/t/playground-errors-in-firefox/15791/2 "2020-11-17T21:56:02Z")
works for me on latest firefox ☹ ---
**Author:** ![adam](https://avatars.discourse-cdn.com/v4/letter/a/4af34b/32.png) [@adam](https://forum.babylonjs.com/u/adam)\ **Post date:** [November 17, 2020, 10:07pm UTC](https://forum.babylonjs.com/t/playground-errors-in-firefox/15791/3 "2020-11-17T22:07:49Z")
I see what was happening. A while ago I was testing a PG and selected BJS 3.3 and forgot to set it back to the latest version. I hope I’m one of the few that run into that issue. It would be cool if there was a way to tell the users that the PG is using a feature that is only available in the latest version. It might not be worth the time to implement, though. edit: or maybe set the PG back to the latest version after a set amount of time. 1 day? 1 week?