Mirador viewer

TypeError: Failed to fetch

{
  "manifest": {
    "error": "TypeError: Failed to fetch",
    "id": "https://digital.libraries.psu.edu/iiif/info/maps1/4257/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
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      "cw-a7ac7f4e-17b9-48fe-82e8-42500c0baac9"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-d6107c20-9eb2-4411-8d2e-dbf517ca4c1a",
    "manifestId": "https://digital.libraries.psu.edu/iiif/info/maps1/4257/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-a7ac7f4e-17b9-48fe-82e8-42500c0baac9"
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}