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_01932/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-4d8b0092-34eb-4bf6-9f76-4439765665fb",
      "cw-62425b8c-1bd8-4cf8-97fe-a684e0f9cea0"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-4e639ab6-0427-4040-b9ea-8208b43d5938",
    "manifestId": "https://iiif.participatory-archives.ch/SGV_12S_01932/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-62425b8c-1bd8-4cf8-97fe-a684e0f9cea0",
    "loadedManifest": "https://iiif.participatory-archives.ch/SGV_12S_01932/manifest.json"
  }
}