# Platform 2025.2 Build Error: npm cannot find /tmp/extensions/package.json

**URL:** <https://community.hubspot.com/t/platform-2025-2-build-error-npm-cannot-find-tmp-extensions-package-json/141145>\
**Category:** APIs & Integrations\
**Tags:** starter\
**Created:** [October 16, 2025, 7:47am UTC](https://community.hubspot.com/t/platform-2025-2-build-error-npm-cannot-find-tmp-extensions-package-json/141145 "2025-10-16T07:47:48Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![FlowViber](https://avatars.discourse-cdn.com/v4/letter/f/7cd45c/32.png) [@FlowViber](https://community.hubspot.com/u/FlowViber)\
**Post date:** [October 16, 2025, 7:47am UTC](https://community.hubspot.com/t/platform-2025-2-build-error-npm-cannot-find-tmp-extensions-package-json/141145/1 "2025-10-16T07:47:48Z")

</div>

Hello HubSpot Developer Community,

I’m experiencing a persistent build failure when trying to deploy UI Extensions cards using the HubSpot CLI. This appears to be a backend platform issue with version 2025.2.

**Setup:**

- Portal ID: 147047874
- Platform Version: 2025.2
- HubSpot CLI: v7.7.0
- Project Type: UI Extensions with React cards

**The Problem:** Every build fails during HubSpot’s npm install phase with the same error:

`npm error path /tmp/extensions/package.jsonnpm error code ENOENTnpm error enoent Could not read package.json: ENOENT: no such file or directorynpm error enoent This is related to npm not being able to find a file.`

**What I’ve Verified:**

- Project structure is correct (hsproject.json, src/app/ structure, proper -hsmeta.json files)
- package.json exists in all correct locations with proper dependencies
- Files upload successfully to HubSpot
- Using absolute entrypoint paths as required
- OAuth and CLI authentication work perfectly
- Local validation passes

**The Issue:** The error occurs on HubSpot’s build servers, not during upload. The build system appears to be looking for /tmp/extensions/package.json on your servers, but this directory either doesn’t exist or isn’t being properly created during the build process.

**Questions:**

1. Has anyone else encountered this /tmp/extensions/ error with platform 2025.2?
2. Is there a workaround or configuration change that resolves this?
3. Should I be using a different platform version?
4. Do I need specific beta enrollment or permissions for UI Extensions?

I found a similar error mentioned in an August 2024 community post about “unexpected error building extension files” that referenced the same /tmp/extensions/ path.

Any insights or workarounds would be greatly appreciated. Thanks in advance for any help. Thanks everyone.

---

<div class="post-metadata">

**Author:** ![chighsmith](https://avatars.discourse-cdn.com/v4/letter/c/77aa72/32.png) [@chighsmith](https://community.hubspot.com/u/chighsmith)\
**Post date:** [October 16, 2025, 10:10pm UTC](https://community.hubspot.com/t/platform-2025-2-build-error-npm-cannot-find-tmp-extensions-package-json/141145/2 "2025-10-16T22:10:07Z")

</div>

Hi @FlowViber,  
Thank you for posting to the Community! I’d like to tag in some Top Contributors to see if they are able to reproduce this -- Hi @mangelet [@Mike\_Eastwood](https://community.hubspot.com/t5/user/viewprofilepage/user-id/9259) and @ChristinaKay Are any of you able to reproduce this? If not, do you have any tips on how to resolve?  
Thank you!  
Cassie, Community Manager

---

<div class="post-metadata">

**Author:** ![FlowViber](https://avatars.discourse-cdn.com/v4/letter/f/7cd45c/32.png) [@FlowViber](https://community.hubspot.com/u/FlowViber)\
**Post date:** [October 17, 2025, 9:50am UTC](https://community.hubspot.com/t/platform-2025-2-build-error-npm-cannot-find-tmp-extensions-package-json/141145/3 "2025-10-17T09:50:12Z")

</div>

Thanks for helping out!