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-b24e368e-4299-4462-b3f8-47025ba25fc2",
      "cw-90cd1a4d-a165-4569-9745-e6accc6aeb5d"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-cc3cafca-70ab-47af-9503-16046b2fca4d",
    "manifestId": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-90cd1a4d-a165-4569-9745-e6accc6aeb5d",
    "loadedManifest": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "canvasIndex": 15
  }
}