TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://colenda.library.upenn.edu/items/ark:/81431/p33s64/manifest",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-c550dc13-355d-4c42-ab52-040759f4e1ce",
      "cw-bcb6f156-a62d-4cdc-820b-ee9839db57ed"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-a7a0ef45-9dcf-4c78-8ddd-62fe02e3c3e3",
    "manifestId": "https://colenda.library.upenn.edu/items/ark:/81431/p33s64/manifest",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-bcb6f156-a62d-4cdc-820b-ee9839db57ed",
    "loadedManifest": "https://colenda.library.upenn.edu/items/ark:/81431/p33s64/manifest",
    "canvasIndex": 2,
    "allowMaximize": false
  }
}