# Vercel preview deployment not allowing Builder visual editor

**URL:** <https://forum.builder.io/t/vercel-preview-deployment-not-allowing-builder-visual-editor/13331>\
**Category:** Visual Editor Help\
**Tags:** visual-editor, nextjs\
**Created:** [March 7, 2025, 4:18pm UTC](https://forum.builder.io/t/vercel-preview-deployment-not-allowing-builder-visual-editor/13331 "2025-03-07T16:18:44Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![richieRich](https://avatars.discourse-cdn.com/v4/letter/r/7bcc69/32.png) [@richieRich](https://forum.builder.io/u/richieRich)\
**Post date:** [March 7, 2025, 4:18pm UTC](https://forum.builder.io/t/vercel-preview-deployment-not-allowing-builder-visual-editor/13331/1 "2025-03-07T16:18:44Z")

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_Please fill out as many of the following questions as possible so we can help you promptly! If you don’t know how to answer or it does not apply, feel free to remove it or leave it blank._

**Builder content link**  
[test | Visual Editor | Builder.io](https://builder.io/content/a4f8596519b34488b4d8e1f22e1fdb1c/edit?activeDesignerTab=0&selectedBlock=builder-83b2b2b4d3ce421ebd30a7877815c45c)

**Builder public api key**  
NEXT\_PUBLIC\_BUILDER\_API\_KEY=4ebce4a686ae4ac0ae1620f8cca02412

**What are you trying to accomplish**  
Have moved to editing on vercel dev deployment [Page Not Found](https://designer-series-git-dev-designer-series.vercel.app/test) and now cannot add new blocks in a brand new page.

Getting lots of errors like:

Failed to load resource: the server responded with a status of 404 () cdn.builder.api which when i click shows me {“status”:401,“message”:“Authorization required”,“detail”:“For help please contact [support@builder.io](mailto:support@builder.io)”}

Uncaught (in promise) Could not evaluate in iframe, doesnt exist!

**Code stack you are integrating Builder with**  
NextJS, react

Do i need to allow vercel connection in builder somehow?

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<div class="post-metadata">

**Author:** ![richieRich](https://avatars.discourse-cdn.com/v4/letter/r/7bcc69/32.png) [@richieRich](https://forum.builder.io/u/richieRich)\
**Post date:** [March 7, 2025, 6:49pm UTC](https://forum.builder.io/t/vercel-preview-deployment-not-allowing-builder-visual-editor/13331/2 "2025-03-07T18:49:05Z")

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A swift reply is very welcome. My client is a little miffed this isn’t working

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**Author:** ![Fernando](https://avatars.discourse-cdn.com/v4/letter/f/779978/32.png) [@Fernando](https://forum.builder.io/u/Fernando)\
**Post date:** [March 10, 2025, 2:02pm UTC](https://forum.builder.io/t/vercel-preview-deployment-not-allowing-builder-visual-editor/13331/3 "2025-03-10T14:02:34Z")

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Hello RichieRich,

Thank you for your questions.

I am trying to understand what you mean by:

> Have moved to editing on vercel dev deployment [**Page Not Found**](https://designer-series-git-dev-designer-series.vercel.app/test) and now cannot add new blocks in a brand new page.

Answering this question:

> Do i need to allow vercel connection in builder somehow?

[Builder.io](http://Builder.io) does not block anything. Possibly, Vercel needs to unblock something as they are hosting.

I was checking the page you shared [Page Not Found](https://designer-series-git-dev-designer-series.vercel.app/test), and I can see all these errors:

 ![](https://us1.discourse-cdn.com/flex020/uploads/builder/original/2X/6/6aa6ac8dee5a6a8e2f1fe74dd3c1462a446cbc44.png)

Just to let you know, you should be able to create an internal ticket with us.

Please check our documentation:

> **[Getting Help - Builder.io](https://www.builder.io/c/docs/help-and-support#contact-us)**
>
> If you have any questions or need support, Builder provides a variety of channels to communicate directly with our team.

Thank you,

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<div class="post-metadata">

**Author:** ![richieRich](https://avatars.discourse-cdn.com/v4/letter/r/7bcc69/32.png) [@richieRich](https://forum.builder.io/u/richieRich)\
**Post date:** [March 10, 2025, 2:43pm UTC](https://forum.builder.io/t/vercel-preview-deployment-not-allowing-builder-visual-editor/13331/4 "2025-03-10T14:43:30Z")

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When i try to create a new page content entry in [builder.io](http://builder.io) and then edit this in the visual editor I get security errors as described. I used to use localhost for using the visual editor and we have since switched to using a vercel preview environment.

Please ignore the hydration errors and look for the error I am commenting on. If you look at one of the first errors it says:

Failed to load resource: the server responded with a status of 404 ()  
it is trying to call the [Builder.io: Visual Development Platform](http://cdn.builder.io/api).

If you click on this error for more details I see another message ‘{“status”:401,“message”:“Authorization required”,“detail”:“For help please contact [support@builder.io](mailto:support@builder.io)”}’

This implies that the [Builder.io: Visual Development Platform](http://builder.io/api) needs to authorize Vercel to access it. How do I do this?

I think this is pretty clear and I appreciate your help.

Thanks,