TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:12029/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-1c5f2c7e-ea6b-45f3-875f-a35b686cb310",
      "cw-0ee77355-ea01-4854-8f90-59f343150226"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-873153a8-bc4c-46ca-9a0f-431ad237ccba",
    "manifestId": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:12029/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-0ee77355-ea01-4854-8f90-59f343150226",
    "thumbnailNavigationPosition": "none",
    "allowClose": false,
    "loadedManifest": "http://cdm17413.contentdm.oclc.org/iiif/2/imagecoll:12029/manifest.json",
    "allowFullscreen": true,
    "allowMaximize": false
  }
}