TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://colenda.library.upenn.edu/items/ark:/81431/p3w08ws3m/manifest",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-b72fdcbd-4eab-40f9-adb5-623c75a3f2c3",
      "cw-d200ebb1-8447-427b-8457-b36a123699a6"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-6f68e11f-0d91-4058-89bd-8412edf3a85d",
    "manifestId": "https://colenda.library.upenn.edu/items/ark:/81431/p3w08ws3m/manifest",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-d200ebb1-8447-427b-8457-b36a123699a6",
    "loadedManifest": "https://colenda.library.upenn.edu/items/ark:/81431/p3w08ws3m/manifest",
    "canvasIndex": 2,
    "allowMaximize": false
  }
}