Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://digital.libraries.psu.edu/iiif/info/maps1/20623/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-ab442131-230d-470a-8b0b-d7d83b89c772",
      "cw-df1280ae-e99d-4b1f-976e-4a42c60741dd"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-bac241db-6539-413b-94b7-fd7ae29a69f6",
    "manifestId": "https://digital.libraries.psu.edu/iiif/info/maps1/20623/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-df1280ae-e99d-4b1f-976e-4a42c60741dd"
  }
}