TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:11957/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-5a9fbad3-a4ab-450d-acc1-74acc4c05a86",
      "cw-0403a2bb-a527-4d98-96d1-cdf4b5c842d2"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-62f5952a-6cd8-4d08-b7cf-cf03b3f1d2e1",
    "manifestId": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:11957/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-0403a2bb-a527-4d98-96d1-cdf4b5c842d2",
    "thumbnailNavigationPosition": "none",
    "allowClose": false,
    "loadedManifest": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:11957/manifest.json",
    "allowFullscreen": true,
    "allowMaximize": false
  }
}