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-b010167f-6c63-480f-bdd5-6b2f86ef9845",
      "cw-02dd9181-8ae9-42ec-92b4-6f995bbbdb5c"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-f0068999-5459-4b7d-ae7c-d7b7ec195e13",
    "manifestId": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-02dd9181-8ae9-42ec-92b4-6f995bbbdb5c",
    "loadedManifest": "https://www.rammses.it/wp-content/manifestoso.json?type=sbn",
    "canvasIndex": 15
  }
}