Internal server error in h when fetching public annotation

Visiting https://hypothes.is/a/2ZcSQKo7EfCeAUP1uxAeig while not logged in shows a "this annotation is not available" message, even though the annotation is public. Inspecting the browser console shows that a 500 error occurred while fetching https://hypothes.is/api/annotations/2ZcSQKo7EfCeAUP1uxAeig. When this URL is visited while logged in, the annotation loads successfully.

When viewing the annotation in context at https://www.seangoedecke.com/seeing-like-a-software-company/, the annotation loads successfully. In this context the annotation is fetched via the search API.