Problem: When adding a Block Theme template part (footer.html) while building our acompletely fresh Block Theme I got this error repeatedly. Couldn’t work out what I’d done wrong. Later that evening while seeing to a matter, it hit me…
The Fix: I’d put the template part in the wrong directory! Theme templates need to go in ‘templates’ directory. Parts i.e. things called with:
<!-- wp:template-part {"slug":"footer"} /-->
…need to go in the ‘parts’ directory.
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