Hi there, thanks for reaching out! Usually this occurs when there’s an issue with the file preview image or its format.

As a first workaround, please try clearing your browser or desktop’s cache or using an incognito window to see if that helps.

If the issue persists, I’d recommend you to reach out directly to the support team: here

Be sure to use your Figma email account, and please include the URL of the Figma file that you are trying to publish, and add support-share@figma.com as an Editor on this file so the support team can take a closer look. Thank you!