Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://iiif.archive.org/iiif/naeb-b020-f12/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-93d5e445-3cb1-4d45-a96e-05228fce20be",
      "cw-327e3c3c-805c-436d-8be0-b9c3c3035aaf"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-7eae377d-7fa5-4a52-86be-01a941e78c20",
    "manifestId": "https://iiif.archive.org/iiif/naeb-b020-f12/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-327e3c3c-805c-436d-8be0-b9c3c3035aaf",
    "thumbnailNavigationPosition": "off",
    "loadedManifest": "https://iiif.archive.org/iiif/naeb-b020-f12/manifest.json",
    "view": "single",
    "canvasIndex": 0
  }
}