# Error when selecting something in inspector

**URL:** <https://forum.babylonjs.com/t/error-when-selecting-something-in-inspector/24737>\
**Category:** Questions\
**Created:** [October 21, 2021, 6:14am UTC](https://forum.babylonjs.com/t/error-when-selecting-something-in-inspector/24737 "2021-10-21T06:14:12Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Anupam\_Das](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/anupam_das/32/16709_2.png) [@Anupam\_Das](https://forum.babylonjs.com/u/Anupam_Das)\
**Post date:** [October 21, 2021, 6:14am UTC](https://forum.babylonjs.com/t/error-when-selecting-something-in-inspector/24737/1 "2021-10-21T06:14:12Z")

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I am getting this error when selecting something in the inspector in move mode.

_**Uncaught TypeError: Cannot read properties of null (reading ‘getEngine’)**_

it does not matter what type of element I select in in the inspector.

Also weird thing is I wasnt getting this error before but getting this now. Wondering if its an API version issue?

“dependencies”: {  
“@babylonjs/core”: “^4.2.0”,  
“@babylonjs/inspector”: “^4.2.0”,  
“@babylonjs/loaders”: “^4.2.0”,  
“axios”: “^0.21.4”,  
“babylonjs”: “^4.2.0”,  
“babylonjs-materials”: “^4.2.0”,  
“babylonjs-serializers”: “^4.2.0”,

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<div class="post-metadata">

**Author:** ![Evgeni\_Popov](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/evgeni_popov/32/4432_2.png) [@Evgeni\_Popov](https://forum.babylonjs.com/u/Evgeni_Popov)\
**Post date:** [October 21, 2021, 8:53am UTC](https://forum.babylonjs.com/t/error-when-selecting-something-in-inspector/24737/2 "2021-10-21T08:53:09Z")

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You can’t mix the different types of packages. I think the “@” packages are for ES6. So, you should remove “babylonjs” and all the “babylonjs-xxx” packages and add the corresponding ES6 packages ("@babylonjs/materials" and “@babylonjs/serializers” - [Babylon.js ES6 support with Tree Shaking | Babylon.js Documentation](https://doc.babylonjs.com/divingDeeper/developWithBjs/treeShaking)).

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<div class="post-metadata">

**Author:** ![sebavan](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/sebavan/32/57_2.png) [@sebavan](https://forum.babylonjs.com/u/sebavan)\
**Post date:** [October 21, 2021, 11:18am UTC](https://forum.babylonjs.com/t/error-when-selecting-something-in-inspector/24737/3 "2021-10-21T11:18:13Z")

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this is really weird you get this in 4.2 ☹ maybe @RaananW would have an idea?

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**Author:** ![RaananW](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/raananw/32/28955_2.png) [@RaananW](https://forum.babylonjs.com/u/RaananW)\
**Post date:** [October 21, 2021, 1:21pm UTC](https://forum.babylonjs.com/t/error-when-selecting-something-in-inspector/24737/4 "2021-10-21T13:21:32Z")

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As @Evgeni_Popov said, it seems like you are including babylon twice - as es66 dependency and as UMD (@babylonjs/core and babylonjs).  
You might be using the UMD version to render your scene, but the es6 to display the inspecor. How exactly - it’s hard to say, but try being consistent with your includes. materials and serializers should also come from the @babylonjs namespace instead of the UMD versions.