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-3f50b08a-c346-43af-9d9c-d73cf54236ab",
      "cw-54801a43-a058-4cb6-a8f9-b54ec39a1a01"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-a64d843f-93d2-41f1-ab9b-a072779ab302",
    "manifestId": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-54801a43-a058-4cb6-a8f9-b54ec39a1a01",
    "loadedManifest": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "canvasIndex": 15
  }
}