# ReferenceError: Monaco is not defined

**URL:** <https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007>\
**Category:** General\
**Created:** [27 June 2024 12:18 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007 "2024-06-27T12:18:41Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Markus\_M](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Markus\_M](https://discourse.nodered.org/u/Markus_M)\
**Post date:** [27 June 2024 12:18 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/1 "2024-06-27T12:18:41Z")

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Hello together.  
I have a new fresh installation of node-red at a Windows Server 2022.  
Latest LTS Version from NodeJS: v20.15.0 and the latest node-red: V4.0.0

I work local at the server and when I start node-red at first time and open the browser I only see the logo in the title.  
By the browser DevTools, I could see this error: "ReferenceError: Monaco is not defined"

In the settings.js I changed the codeEditor from "monaco" to "ace". Now it seems to work but why monaco is not working? It is a fresh installation of all components. Can anyone explain me?

Best regards,  
Markus

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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [27 June 2024 13:25 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/2 "2024-06-27T13:25:05Z")

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Bad install?

Something blocking the download/transfer of the monaco code? (check the network tab as you refresh, look for non 400s)

Try incognito/private (no plugins) mode

Try a different browser.

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<div class="post-metadata">

**Author:** ![Markus\_M](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Markus\_M](https://discourse.nodered.org/u/Markus_M)\
**Post date:** [28 June 2024 05:08 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/3 "2024-06-28T05:08:06Z")

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Hi Steve,  
Thank you for your response.  
When I use the incognito mode I got the same errors.  
Only I can use the MS-Edge browser in our organization - always that's not easy 🙂

I looked at the browser dev-tools when I use the ACE editor. Also there are some errors but the ui is working well.

I think you are right, that I have a bad install. But it's crazy there are no errors in the logs files for the node-red install. Now, I try a new install.

Best regards,  
Markus

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [28 June 2024 06:36 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/4 "2024-06-28T06:36:48Z")

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> [@Markus\_M](#):
>
> looked at the browser dev-tools when I use the ACE editor

What if you try to use Monaco? That may indicate what the problem is.

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<div class="post-metadata">

**Author:** ![Markus\_M](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Markus\_M](https://discourse.nodered.org/u/Markus_M)\
**Post date:** [28 June 2024 06:56 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/5 "2024-06-28T06:56:39Z")

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![screenshot](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/d/9/d93a4c6d4d7c40577e28875fa7d0e66afed8f53e.png)  
It seems that monaco is not available. -\> "...is not defined"

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [28 June 2024 07:35 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/6 "2024-06-28T07:35:01Z")

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What do you see on the network tab?

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<div class="post-metadata">

**Author:** ![Markus\_M](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Markus\_M](https://discourse.nodered.org/u/Markus_M)\
**Post date:** [28 June 2024 08:06 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/7 "2024-06-28T08:06:07Z")

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![screenshot](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/6/2/628032f036f80bfa2e2d14cb47ecd5611968027f.png)

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<div class="post-metadata">

**Author:** ![Markus\_M](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Markus\_M](https://discourse.nodered.org/u/Markus_M)\
**Post date:** [28 June 2024 08:37 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/8 "2024-06-28T08:37:51Z")

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Hi.  
I'm so sorry for this effort.  
I found out the problem. That's really stupid.  
The server is a fresh install but the browser MS-Edge has the Version 86. OLD! Currently I have to wait for the update by our IT.  
Until this I got a approval to test with google chrome. -\> Red-Node works fine.

Have a nice weekend.

Best regards,  
Markus

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [12 July 2024 08:38 UTC](https://discourse.nodered.org/t/referenceerror-monaco-is-not-defined/89007/9 "2024-07-12T08:38:04Z")

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