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/p16022coll246/215/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-876f1993-d7b4-4885-bd82-d47ec83d1c96",
      "cw-b4466b73-fe3f-4b4f-a8ea-4d2c8b64b51e"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-aaaadfa7-6324-437c-9b17-bd881cfce7cb",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/215/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-b4466b73-fe3f-4b4f-a8ea-4d2c8b64b51e"
  }
}