Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://sandbox.zenodo.org/api/iiif/record:167491/manifest",
    "isFetching": false
  },
  "viewer": null,
  "window": {
    "canvasId": "https://sandbox.zenodo.org/api/iiif/record:167491/canvas/cover2.jpg",
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-4f0fa77d-458e-49db-a677-6330e17b12b8",
      "cw-43af0fa4-f5ef-4b9e-bbde-c32e5e29924b"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": true,
    "id": "window-dfafe1d5-cec2-4c13-b406-75d57786f1f8",
    "manifestId": "https://sandbox.zenodo.org/api/iiif/record:167491/manifest",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-43af0fa4-f5ef-4b9e-bbde-c32e5e29924b",
    "thumbnailNavigationPosition": "far-right",
    "visibleCanvases": []
  }
}