Mirador viewer

SyntaxError: Unexpected token 'I', "I don't kn"... is not valid JSON

{
  "manifest": {
    "error": "SyntaxError: Unexpected token 'I', \"I don't kn\"... is not valid JSON",
    "id": "https://iiif.participatory-archives.ch/SGV_12S_01122/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-3ecc3d7d-7645-408a-8303-7ac54ee0c3a1",
      "cw-09afd2a6-a5d9-49c7-8f1d-ad99164bb01f"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-3b199287-3a50-4946-bfe1-210c64e42f48",
    "manifestId": "https://iiif.participatory-archives.ch/SGV_12S_01122/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-09afd2a6-a5d9-49c7-8f1d-ad99164bb01f",
    "loadedManifest": "https://iiif.participatory-archives.ch/SGV_12S_01122/manifest.json"
  }
}