Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://iiif.archivelab.org/iiif/christentumundw00sellgoog/manifest.json",
    "isFetching": false
  },
  "window": {
    "canvasId": "",
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-ef15258f-8c01-48a7-813c-483639be0fd4",
      "cw-a0703ece-bf89-48c7-a136-f0acc8ffc8b6"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "my-mirador-window",
    "manifestId": "https://iiif.archivelab.org/iiif/christentumundw00sellgoog/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-a0703ece-bf89-48c7-a136-f0acc8ffc8b6",
    "thumbnailNavigationPosition": "far-bottom"
  }
}