Deployment has errors only after publishing

Hi there,

I attempted to update my website yesterday (only updating text and CSS) and observed strange behaviour when attempting to publish the changes. It’s fairly simple static single-page website, using React and Gatsby.

  • The updated site builds and loads locally without errors
  • The updated site builds and loads as a preview on Netlify without errors (Preview button on a specific Deploy page)
  • When I publish the updated site, the published site has an error in the console and some functionality is broken.

It is difficult to determine the source of the error, because everything is minimized in the production deploy. FWIW, this is the error log: TypeError: a is not a function. (In 'a("atStart",!0)', 'a' is an instance of Object)

I’m not sure how to proceed with diagnosing the problem here. I can only reproduce this issue by publishing the latest commit, which breaks functionality on a live site (for now, I have rolled back to the previous version).

I’d appreciate any pointers regarding why the deployment previous could have different behaviour than the published deployment. Thanks!

You have not mentioned your site at all, so there’s no way we can check anything about this.

Hi, thanks for taking the time to respond.

I’m sorry I didn’t include the site in the original post. I omitted this to avoid confusion because, at the time of posting, I had reverted the live site back to an older version, in which the error did not reproduce. For reference, the live site is and the Netlify project name is

Returning to this today, I can’t reproduce the error at all on the live site, using the same process from earlier. I’ll follow up here if I can reproduce this issue again.