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/p16022coll246/373/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-07607c96-2959-4acd-a6d1-8205462311a7",
      "cw-300a9ec7-f155-4673-a979-50265e8f5e4e"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-dd2cae85-ba18-4fdf-83de-e65f75b4c328",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/373/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-300a9ec7-f155-4673-a979-50265e8f5e4e"
  }
}