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/p16022coll624/480/manifest.json",
    "isFetching": false
  },
  "window": {
    "collectionIndex": 0,
    "companionAreaOpen": true,
    "companionWindowIds": [
      "cw-960eb1a3-5ea7-476b-b388-fd7f07390e3d",
      "cw-a3d4f8ae-7600-488c-bb05-6c47c095e117"
    ],
    "draggingEnabled": true,
    "highlightAllAnnotations": false,
    "id": "window-2c9ff738-14d4-407d-8be0-460739becdca",
    "manifestId": "https://cdm16022.contentdm.oclc.org/iiif/info/p16022coll624/480/manifest.json",
    "maximized": false,
    "rangeId": null,
    "rotation": null,
    "selectedAnnotations": {},
    "sideBarOpen": false,
    "sideBarPanel": "info",
    "thumbnailNavigationId": "cw-a3d4f8ae-7600-488c-bb05-6c47c095e117"
  }
}