Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://digital.libraries.psu.edu/iiif/info/maps1/21515/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
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      "cw-36352656-d099-47c0-89a4-32e1578bc2b3"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-6bbbb83f-a909-43fa-9f6c-0cf0de43637b",
    "manifestId": "https://digital.libraries.psu.edu/iiif/info/maps1/21515/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-36352656-d099-47c0-89a4-32e1578bc2b3"
  }
}