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/p16022coll246/356/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-fa6f3b2d-b1fd-4908-b6b1-7c46ced9c950",
      "cw-cbe43413-3e5f-41ce-b327-0af448600bc5"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-8b6846c0-a927-440d-a07c-3d1744b81497",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/356/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-cbe43413-3e5f-41ce-b327-0af448600bc5"
  }
}