Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://dam.sma.unibo.it/smaunibo/containers/4DelWqQ/manifest",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-26ba7dea-a348-4d73-8733-7798d3640253",
      "cw-72d8d7a7-4da3-4c49-85ad-f764a775a72b"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-bdc65b88-740a-4d29-b734-303561ff5db9",
    "manifestId": "https://dam.sma.unibo.it/smaunibo/containers/4DelWqQ/manifest",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-72d8d7a7-4da3-4c49-85ad-f764a775a72b"
  }
}