Export view as XXX: not working

Using a newly installed `higlass-manage` which has pulled the latest image (3d old `33b57bb8b9c0`).

*Export view as link* is not working. Looking in the logs I see:

`hg-data/error.log`

```
2019/06/13 11:56:01 [error] 16#16: *82 readv() failed (104: Connection reset by peer) while reading upstream, client: 172.20.240.254, server: , request: "POST /api/v1/viewconfs/ HTTP/1.1", upstream: "uwsgi://127.0.0.1:8001", host: "172.27.81.12:8888", referrer: "http://172.27.81.12:8888/app"
```

`hg-data/hgs.log`

```
[13/Jun/2019 12:01:02] WARNING [django.request:228] Forbidden: /api/v1/viewconfs
```

*Export view as PNG* is not working, logs don't show any errors.

SVG and Json are working.