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_00927/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-91d1a28f-5182-4c05-b062-721a2535a337",
      "cw-e5b2c526-8bc8-404b-a695-a73104c0e98b"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-65cdf047-e6ea-4f4b-92b3-d200a2ff82e5",
    "manifestId": "https://iiif.participatory-archives.ch/SGV_12S_00927/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": true,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-e5b2c526-8bc8-404b-a695-a73104c0e98b",
    "loadedManifest": "https://iiif.participatory-archives.ch/SGV_12S_00927/manifest.json"
  }
}