TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://dam.sma.unibo.it/smaunibo/containers/wdVG5On/manifest",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-c007dc57-815f-499e-b168-26724fa068fa",
      "cw-69571112-baa9-43e7-8175-6d1d01cfdc30"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-8bc1443e-ecf5-45e5-a3c9-b7d9773c31f9",
    "manifestId": "https://dam.sma.unibo.it/smaunibo/containers/wdVG5On/manifest",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-69571112-baa9-43e7-8175-6d1d01cfdc30",
    "thumbnailNavigationPosition": "far-bottom"
  }
}