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-e2a3c258-ec60-4486-af5f-e53043516022",
      "cw-4a5accc1-f361-4bf3-932d-50d75e702303"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-18ff6033-412a-4c47-8445-c8d56b15ad52",
    "manifestId": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-4a5accc1-f361-4bf3-932d-50d75e702303",
    "loadedManifest": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "canvasIndex": 15
  }
}