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/p16022coll246/397/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-7bb6eae3-66b6-4bc3-a825-fe503c88c38c",
      "cw-0d98cf15-c610-46c9-b3e0-fc016497383a"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-73b8355a-0b53-411f-8959-732d091c96f7",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/397/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-0d98cf15-c610-46c9-b3e0-fc016497383a"
  }
}