Mirador viewer

SyntaxError: Unexpected token '<', "<!DOCTYPE "... is not valid JSON

{
  "manifest": {
    "error": "SyntaxError: Unexpected token '<', \"<!DOCTYPE \"... is not valid JSON",
    "id": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/246/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-6b1de591-9246-478e-afe5-29ecf221de08",
      "cw-a1c077fa-2748-4ce6-9592-40eeb001fab2"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-979f3a42-0eae-4860-90f5-c3660fa552e5",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/246/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-a1c077fa-2748-4ce6-9592-40eeb001fab2"
  }
}