TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:6957/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-5bd96023-db9f-4cc0-b4e0-bf02b1c19d24",
      "cw-51f0f16e-656b-4225-938f-3ff1cf0d4603"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-397850f1-8a39-474d-9a65-c6774a206347",
    "manifestId": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:6957/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-51f0f16e-656b-4225-938f-3ff1cf0d4603",
    "thumbnailNavigationPosition": "none",
    "allowClose": false,
    "loadedManifest": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:6957/manifest.json",
    "allowFullscreen": true,
    "allowMaximize": false
  }
}