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/p16022coll246/434/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-9ee1ddad-9d29-4fcb-a7c0-f827f33daaba",
      "cw-ae54b550-cf5a-4f4b-b398-c7a572aa393f"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-735660f8-014e-4b30-95ec-d236c514f4cf",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/434/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-ae54b550-cf5a-4f4b-b398-c7a572aa393f"
  }
}