Mirador viewer

TypeError: Failed to fetch

{
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    "error": "TypeError: Failed to fetch",
    "id": "https://digital.libraries.psu.edu/iiif/info/maps1/20748/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
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    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-8e5f26be-ecc4-4838-aa0c-3d9c075c8cc1",
    "manifestId": "https://digital.libraries.psu.edu/iiif/info/maps1/20748/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-b5f22c2e-9dc3-497f-a849-56495109630c"
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}