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/p16022coll246/166/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-1ec578e7-2a06-4c4e-a322-ebd96fef0918",
      "cw-afda533a-92e6-4f48-bf68-cf0fc499af21"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-2100622b-42b8-4cf6-9650-412598bf7fb3",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll246/166/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-afda533a-92e6-4f48-bf68-cf0fc499af21"
  }
}