Getting 500 when accessing the /branches API on my repo

I attempted to GET this REST API URL a couple of times, and I'm failing to retrieve data.

The API I'm accessing: https://api.bitbucket.org/1.0/repositories/atlassian/aui/branches

The responses I'm getting (after ~28 seconds):

{"type": "error", "error": {message: "Internal server error", id: "c8b2af981c74458f91359b7e1c0e9c79"}}
{"type": "error", "error": {"message": "Internal server error", "id": "9e7d334df34947198914e0fff334f492"}}

This is happening irrespective of whether I add an authorization:Bearer... header or not.