Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-21fd5e54-2f32-4f66-baa7-7eba620b17c2",
      "cw-32a92eb7-3981-4ffc-9df9-2eef9c73ad36"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-42ce5b84-e34c-4cae-b468-2e7de2991594",
    "manifestId": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-32a92eb7-3981-4ffc-9df9-2eef9c73ad36",
    "loadedManifest": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "canvasIndex": 15
  }
}