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-7c6c7caf-93cd-4a98-a78a-248f4c8a69eb",
      "cw-7f5bbe78-d98f-476a-85c3-809337f44c6b"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-ffb582b4-13d1-4852-b2f8-36c6c878baee",
    "manifestId": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-7f5bbe78-d98f-476a-85c3-809337f44c6b",
    "loadedManifest": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "canvasIndex": 15
  }
}