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/p16022coll246/240/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-94f5f9c5-40d7-4471-8055-13660b1f2205",
      "cw-cfd92d0d-d479-4fa5-b55d-c09c13d29bf3"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-5bc7755d-d7f7-43e8-9708-4ef85a5ce904",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/240/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-cfd92d0d-d479-4fa5-b55d-c09c13d29bf3"
  }
}