Prismic previews not working after migrating to Netlify from Gatsby Cloud

Hi, we’ve recently migrated our site from Gatsby Cloud to Netlify and I’m trying to get the “Preview” functionality working.

I’m trying to run the previews locally in a dev environment at the moment. When I click the “Preview” on Prismic, it opens up the preview page on http://localhost:8000/preview/… and I do see the page loading the background with a popup saying, “Fetching Preview”. However, after a few seconds, I get an error saying, “Error in function assertType in ./node_modules/gatsby-source-prismic/dist/index.js:22, Value is not expected type Image”.

I’m using gatsby v4.25.7.

Can someone please let me know if there’s a way to fix this error?


If this is happening locally, I’m not sure how this is a Netlify issue. Could you please confirm?