TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "http://cdm17413.contentdm.oclc.org/iiif/2/findingaids:421/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-33532744-3f0f-45fa-9cf5-094ace378642",
      "cw-1423da5f-dd50-46d0-af4a-0003582bad29"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-bcdfb58a-effb-470c-99bf-5f3c1df6a63d",
    "manifestId": "http://cdm17413.contentdm.oclc.org/iiif/2/findingaids:421/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-1423da5f-dd50-46d0-af4a-0003582bad29",
    "thumbnailNavigationPosition": "none",
    "allowClose": false,
    "loadedManifest": "http://cdm17413.contentdm.oclc.org/iiif/2/findingaids:421/manifest.json",
    "allowFullscreen": true,
    "allowMaximize": false
  }
}