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/p16022coll230/487/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-f4a563a6-c3a3-47ba-8b59-ce23e2e22884",
      "cw-7d017332-9729-482d-b3e7-f007fbceeced"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-50093a65-2276-425c-acaf-b5afd8deadb4",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll230/487/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-7d017332-9729-482d-b3e7-f007fbceeced"
  }
}